crystal ball issue 21 vol spring 2012

CRYSTAL BALL | CRYSTAL BALL | Periodical of the New ZealaNd avalaNche commuNity 1

NEW ZEALAND MOUNTAIN SAFETY COUNCIL

PERIODICAL OF THE NEW ZEALAND AVALANCHE COMMUNITY

DISCOVERMORE, SAFELY

vOLU

ME

21

SPR

ING

201

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www.avalanche.net.nzwww.mountainsafety.org.nzwww.adventuresmart.org.nzwww.incidentreport.org.nz


CONTENTS

01 welcome

02 learn at every opportunity

02 Snow and avalanche committee

03 News bites

07 avalanche.net forecaster summaries

23 Stage 2 avalanche: a participant’s perspective

25 applying search theory and coordinated incident management to avalanche rescue

31 ruapehu’s avalanche hot house

34 airbags

35 comparing the Seasons

37 Parting pics

WELCOMEit’s been a busy winter working on a wide range of things including the education programmes and public outreach events, the Backcountry avalanche advisories, the info-ex and regional Sar-exercises.

it was a tumultuous year for weather across the country punctuated by early snow, torrential rain, fluctuating freezing levels and gale force winds. as i write, snow is still falling in the canterbury high country and the skiing is as good as it has been all winter but the avalanche danger continues to float between ‘considerable’ and ‘high’. we even had our first ‘extreme’ rating of the year. then just to confirm the advisory, two climbers got caught on a soft slab in arthur’s Pass and luckily walked away with their lives.

it has been a year of ‘lucky’ near misses. we started with the two climbers on mt taranaki then continued with a range of structures damaged, people going for rides or triggering sizable slides. the closest ‘lucky escape’ were the 35 individuals who were narrowly missed by the three simultaneous natural events on mt ruapehu. we are told that many near misses add up to an accident and it certainly emphasises that we need to keep on working hard to inform and educate people before they head out into the mountains.

the winter was also a test for a number of new initiatives, including the redeveloped info-ex, the updated avalanche awareness course resources, new plastic decision making card and the avalanche Safety and avalanche rescue brochures which were all very popular.

after the less than satisfactory system in 2011, the new and simplified info-ex was unanimously welcomed. we worked hard to create a programme that would satisfy the industry’s needs and it was pleasing to be heading in the right direction. the info-ex is an important tool for mSc and the safety management systems of snow sport operations, and we will continue to take feedback and direction for future development.

the www.avalanche.net.nz received international recognition at the international Snow Science workshop (iSSw) in alaska. Both the canadians and americans publically acknowledged the development work done on the site and the uS forecast centres engaged with us in the redevelopment of their website. it is great to see the international community attaining some consistency in the avalanche advisory format and descriptions.

as always, please print this off and pin to your noticeboard or feel free to save paper and forward on.

See you out in the hills.

- Andrew ‘Hobbie’ Hobman, Avalanche and Alpine programme manager

the crystal Ballvolume 21, Spring 2012

Editor: Gordon Smith

Managing Editor: andrea corrigan

Designer: dani millar

Cover Photo: charlie hobbs

thank you to the contributors for giving permission to reproduce their material.

copyright © New Zealand mountain Safety council 2012.all rights reserved.All opinions expressed in this magazine are not necessarily those of the New Zealand Mountain Safety Council. While efforts are made to check facts are accurate, responsibility lies with the author.

Editorial and Advertising enquiries

do you have something to say or show? we would like articles relating to the professional avalanche industry, public avalanche safety, teaching tips, research papers, accounts of avalanche events, book and gear reviews, event listings, interviews, letters to the editor, and humorous stories related to avalanches.

we are also looking for winter mountain photography of avalanches, touring, terrain, skiing, snowboarding, active control work, backcountry recreation or avalanche awareness activities.

for more information please contact:

andrew hobmanTel: +64 3 371 3724Fax: +64 4 385 7366Email: [email protected]

to have your voice heard at the Sac committee, contact your industry representative, or email: [email protected]


CONvENOr’S COrNEr // LEarN aT EvEry OppOrTuNiTy

whether you are packing your gear for that last touring mission or have already gone surfing, another Kiwi season draws to a close.

it seems to have been a reasonably safe one for most, and our third consecutive season without an avalanche fatality. of the 400-or-so reported avalanches this year, only 5% were accidently triggered by people. less than half of these became caught up in the moving debris and resulted in minor injuries.

although statistics give an indication of trends, they are often directly related to the number of storm events per season. even positive trends can be little comfort to the two people that were injured in avalanches this year.

Convenor: Peter Bilous (Otago Polytech & AEWG rep)

Members: dr i owens (University of Canterbury)don Bogie (Department of Conservation) arthur tyndall & Nick Jarmin (Club Ski Fields) wayne carran (Works Infrastructure)andy hoyle (SAANZ North Island)John hooker (SAANZ South Island) Pete Zimmer (LandSAR)Kevin Boekholt (NZMGA)andrew hobman & Gordon Smith (NZMSC)

Above: the Snow and avalanche committee, october 2012

from left: don Bogie, andy hoyle, Pete Bilous, dr ian owens, Kevin Boekholt, Gordon Smith and andrew hobman

absent in picture: arthur tyndall, Nick Jarmin, wayne carran, Pete Zimmer and John hooker.

SNOw aNd avaLaNChE COmmiTTEE (SaC)

as much as we would like to think that our public advisory messages and avalanche safety education is helping reduce avalanche involvements, the decisions made by you before ascending or descending your favourite line ultimately comprise these stats.

a special shout out to hobbie and Gordie for taking all the feedback regarding our industry sharing tool and coming up with the version of info-ex that is vastly improved. a lot of their time went into finding and modifying a product to meet the needs of industry and then train users nationally on its use. well done lads. education is targeted to get a similar shake-up in the coming year.

- Peter Bilous Snow and Avalanche Committee Convenor

The mission of MSC’s Snow and Avalanche Committee:to provide expert advice and support to the council on appropriate strategies to foster public safety in snow environments including:

• overseeing the training, assessments and qualifications of instructors to ensure that national standards are maintained and enhanced

• overseeing the professional training programmes of all providers as required

• monitoring, research and review trends in snow and avalanche activities to ensure the council remains the leading authority for safety in this environment.

To have your voice heard at the SAC committee, contact your industry representative or email [email protected]


NEW ZEALAND’S FirST BCA BEACoN ChECkEr iNSTALLED AT CrAigiEBurN VALLEy Ski ArEA craigieburn valley Ski area and Sportive NZ have worked together to provide craigieburn skiers with the first Bca beacon checker in New Zealand. this new beacon checker not only has an audio beep to let you know that your beacon is functioning, but has a visual green circle displayed as well. the unit is completely weatherproof and is easy to install. with the rapid increase in backcountry skiing and snowboarding, craigieburn and Sportive NZ are working together to bring avalanche awareness to their skiers and riders. having the right equipment and knowing that it functions properly is an important step in backcountry user safety.

NEwS BiTES

TECh FiLE uPDATE

further to our article last issue on the use of smart phones within snow safety, we have had alot of requests to supply more information on how more accepted technology can help perform some of the functions traditionally done on paper. here is a list of web links to tools that can be used in the snow safety office to prepare, store, enter, analyse, and share data. most links will provide their own documentation or video explanations.

industry sharing tool:

• NZ infoex (subscription) www.avalanche.net.nz

Snow profiling software:

• Snowpilot (free download) www.snowpilot.org

• Snowpro (subscription) www.gasman.com

Digital Atlas Development:

• Google earth (free download) www.google.com/earth

• NZ topographical maps – able to be integrated into Google earth (free download) www.topomap.co.nz

Above: Some screenshots of selected websites as mentioned in left article.

Above: Nick Jarmin, Craigieburn Valley Operations Manager demonstrates a positive transceiver check on his way to work.


AVALANChE AWArENESS For ‘SLEDDErS’

in response to the increasing numbers of the sled community using more challenging terrain, the NZmSc will be running an Avalanche Awareness course specifically for snowmobile users in the 2013 winter season. this will be a joint venture between the mountain Safety council, overSnow tours, rob rosa Station, and the Southern hemisphere Proving Grounds. it will be held up on the Pisa range next July.

Just like skiers, snowboarders, climbers, and trampers who need to make decisions on where to go, or even if to go, snowmobilers must make the same choices. as machines become lighter, more powerful, and have better traction, skilful riders can now easily get up into the very steep terrain that wasn’t possible in the past. the consequence of their terrain choice decisions is likely to become greater. to be a skilful rider does not automatically mean you possess avalanche awareness skills.

many of the riders we met over the course of this year’s season had done some good work in equipping themselves with safety equipment, seeking out a backcountry avalanche advisory, and being respectful of other users on the Pisa range. By their own admission however, all were in need of more safety equipment practice, and more importantly, want to know how they can make more objective and informed decisions about which terrain they should be using on any given day.

we will cover these key fundamentals, and tailor the course to suit how snowmobilers use and approach terrain. if you are interested in finding out more about this new course, contact Gordon Smith via email: [email protected]

NZ’S FirST SkiDoo hiLL CLiMB EVENT

roundhill Ski area hosted New Zealand’s first snowmobile hill climb event on Saturday 18 august. the ‘high marking’ event had 24 entrants, most of whom were privateers. New snow conditions made the usually easy-to-climb face challenging, and only three of the riders made it past the half way mark on the 1.7km long, 650m vertical rise.

the inaugural honours go to South american Pablo, (pictured below with trophy) who is based in Queenstown. he left the others far behind, and was the only competitor to reach the summit.

event organiser and roundhill operations manager Simon murrell came in second, followed in third place by the ‘crouching tiger, hidden dragon’ profile of cardrona’s Gary husband.

Planning is already underway for next year’s event with major sponsorship coming on board to help promote ‘sledding in the south’.

for more information on the 2013 event, contact Simon murrell via email: [email protected]

kiWi No.8 WirE AirBAgSoLuTioN.

Ben corcoran from the NZ defence force has come up with a solution for those who feel that current airbags are a bit tight on volume. they purchased aBS vario packs and got twin Needles in christchurch to make up a sack suitable for multi day camping. it’s 65litres with a large pocket on the front for the shovel and probe. Ben reports that it’s still a work in progress that needs some tweaks, but appears very functional.


Website statistics

Between July 1 and September 30 2012, approximately 50,500 visits were made to www.avalanche.net.nz by over 14,500 people, with almost 150,000 pages viewed. this is an improvement of approximately 20% from the 42,000 visits over the same period last winter.

this season more than 7,000 visits were made via mobile devices, which is an increase from 5% to 14% of total visits.

a little over half of these were on apple devices, the rest were via the android operating system. unsurprisingly, the avalanche forecast pages are by far the most viewed pages on the website.

avaLaNChE.NET.Nz


youTube - www.youtube.com/user/nzavalanche

at both ends of the country in tongariro, and in the Southern lakes, we have had regular video field updates on conditions. our intention is to have these weekly, and also at times when we need to get special advice out to the public. the avalanche centre’s videos have been very popular, and have been viewed more than 8000 times. field techniques and guidelines on how to perform snowpack tests are always popular.

alongside the www.avalanche.net.nz website, we have a growing profile on social media sites. these are gaining a modest following, and serve to engage and build a community of backcountry users. they offer another way for the public to share their snow and avalanche observations. here we describe how we use the different mediums, and what kind of following has been generated.

Facebook - www.facebook.com/NewZealandAvalancheCentre

aside from general interest posts, images and related news, we update facebook when avalanche warnings move to hiGh. we also repost/share news and observations from the field. a breakdown of our 424 facebook friends is below:

Twitter - www.twitter.com/NZMSCavalanche

any posts on twitter also get directed and posted up to our facebook page. we use this to advise when danger levels rise to hiGh. People who follow our twitter feed, can get automatic alerts sent to their phones as well as see this within facebook.

SOCiaL mEdia


the Backcountry avalanche advisories produced by the New Zealand mountain Safety council continue to be popular amongst recreational users of alpine areas. this winter more than 14,500 people regularly viewed the forecast pages to seek advice via www.avalanche.net.nz.

the following regional summaries cover the period July 1 to September 30 2012. Since then, october has brought several intense cold Nw storms to the South island’s main divide, elevating danger levels, and even closing the

NEw zEaLaNd avaLaNChE rEpOrT 2012

key to Danger Scale graphics:

arthur’s Pass road until it could be cleared. this will likely guarantee plenty of snow for the popular high elevation ski touring routes for weeks to come.

- Gordon Smith Assistant Avalanche programme manager New Zealand Mountain Safety Council

avaLaNChE.NET.Nz // 2012 wiNTEr Summary

5 Extreme4 High3 Considerable2 Moderate1 LowReport not updated that dayNo rating insufficient informationNo rating insufficient snowNo rating centre closed for season

click here to view larger version

http://www.avalanche.net.nz/Files/2012-Danger-Summary-July1-to-Sept-30.jpg



ruapEhu aNd TONGarirO CrOSSiNG // ryaN LEONG

oVErViEW

the 2012 season was one full of contrasts, and a bit of a rollercoaster in many ways. Great coverage to start, then came a rain event that could only be described as offensive. No avalanche activity for the start of the season, then straight into size 2.5 naturals on paths that have no recorded history, and an extended stint on considerable danger. there was even a volcanic eruption on mt tongariro which limited access to certain backcountry terrain for a good slice of the season.

WEAThEr

things began with a powerful North west storm in mid June which deposited good amounts of snow to the region, making backcountry access easy from the beginning of the season. the North west – South west systems continued until the end of June which kept the snowpack growing.

a standout feature of the weather for July was the persistent anticyclonic blocking which resulted in a sustained easterly flow. the other stand out feature (that people will remember more vividly) was a significant rain event during the middle of the month which did large amounts of damage to the snowpack, and almost spelt the end of the season. Some local old time crusties were saying it was the worst rain damage in recent history!

august saw a welcome return to a more normal weather pattern with North west storms bringing good amounts of snow above 1400-1600m, followed by brief clearances coming with the South westerly change before the next system arrived.

this continued into mid September which finally brought about some settled spring weather. here’s hoping for a continuation of the settled weather for the remainder of the season so we can all get out and enjoy some spring touring.

SNoWPACk

the snowpack started in its usual ruapehu fashion – the first few storms filling in the gaps of the boulder strewn ground cover until slopes approached threshold. from late June/early July cold clear periods combined with the early season snow cover to develop thin near surface facetted layers on shady slopes above 1900m. the closely following rain deluge saw that these initial layers were short lived. the July – august period saw some significant surface hoar growth above 2300m – up to 8mm and very widespread for this region. Strong winds destroyed these layers, however very isolated areas did persist and become buried, but were not responsible for any significant events.

august saw some significant snowfall with winds from the westerly ½ which resulted in healthy sized windslabs and the associated storm snow instabilities. during this period a facetted layer had been observed around 80cm deep which

remained reactive in tests and showed good propagation propensity during mid august. from this point on, the top ups continued with some significant accumulations (up to 2.5m) during early – mid September. weaknesses formed within the new slabs due to wind and temperature variations, but these were relatively short lived.

as of late September the snowpack has transitioned into a thoroughly enjoyable (for those traveling in Northern parts of the region) spring pack. the melt freeze cycle is well established and all previous instabilities have faded away into the background hiss of silky spring corn. the coverage is great, so here’s looking forward to some great touring into early summer.

AVALANChE ACTiViTy

the 2012 season saw some large events in the ruapehu backcountry, as well as a few healthy sized slabs out of features that are not regular performers.

the mid June storm cycle produced limited avalanche activity due to only isolated paths being at threshold.the rain event from mid July was responsible for the only recorded avalanche observation in the tongariro/Ngauruhoe region. this was a size 1.5 wet slab on the east face of tongariro.

the earthquake on July 3 which was centered 60 km Sw of opunake was felt throughout the central plateau, and groomer drivers from turoa ski field reported a small natural cycle around the same time. was this the regions first recorded seismic triggered cycle?

Some medium – large natural cycles occurred as a result of the sustained storm cycles of august. around the plateau area some well supported slopes produced staunch slabs up to 1.2m deep. on august the 5 a large natural cycle occurred above turoa ski area with slabs in the 2-3 size range. this was most likely the result of rapid warming due to a drop in wind and re radiation from afternoon cloud cover. there were scores of (unaware and uneducated) skiers / riders hiking directly up through this terrain during the cycle and it is only by sheer luck that there were not multiple involvements. this highlights the need to keep pushing avalanche awareness and education in the North island. >>




COLLaBOraTiON wiTh mETSErviCE

we have had a very productive and mutually beneficial relationship with metservice this season.

this has resulted in the avalanche advisory website being promoted via their Powder Watch e-newsletter which went out to thousands of subscribers.

we also created some web banners which were displayed in various places throughout the mountains and Parks section of the metservice.com website potentially reaching hundreds of thousands of outdoor enthusiasts.

we look forward to working with met Service next year and continuing a great working relationship.

CoNCLuDiNg rEMArkS

the backcountry avalanche advisory spent some sustained time on considerable during august. regular field trips into the backcountry came back with consistent observations of natural slab cycles which justified this rating. although there was a very close call during the august 5 natural cycle, it has been inspiring to see an increase in the number of well equipped, well informed backcountry parties in the region.

Big thanks are due to the ski patrol/snow safety teams at whakapapa, turoa, and tukino for contributing information and observations which have been invaluable for the advisories, and also to co-forecasters andy hoyle and mike lundin. ▲


WEAThEr

the first major weather event in June saw enough snow on the upper mountain to bury two climbers in an avalanche, although the snow pack remained shallow with very little or any significant weather events to write about until the school holidays in July.

the weather system that rolled though in July brought plenty of snow to low levels allowing the local manganui Ski field to open for the last week of the school holidays with excellent blue sky skiing. what seems to be a common theme for mt taranaki is that a heavy rain event followed a week later destroying most of the snow and good skiing.

as we headed into august the weather took a turn for the better, if you are a keen gardener with mostly fine settled weather, more like springtime conditions. one last significant snowfall hit the mountain in September once again bringing snow to low levels and great skiing and yes a few days after the storm, rain returned. as this goes off for print we are well into springtime conditions.

AVALANChE ACTiViTy

this winter saw two climbers get caught in an avalanche early season, with minimal snow depth but enough to bury two people. Strong winds had created a wind slab on Northerly aspects, with many large rocks still present on surrounding slopes - it would have been easy to assume the risk was minimal. the debris from the avalanche was several hundred meters long and 20m wide – both climbers were buried, with one a full burial.

luck would have it that both the climbers were close when the avalanche stopped. it was pure luck that one of the climbers was only partially buried and got out. it was sheer luck that his climbing companion had his hand sticking out of the snow. and it was also lucky the injured climber using only his hands was able to dig his companion out. Both are very fortunate that they are alive. Neither had any avalanche rescue equipment, i am very happy to report that this event did not result in taranaki’s first avalanche fatality. No other significant avalanche events have been recorded or reported this season, the potential has been there with some of the weather events and snow conditions, but no failure.

SNoW PACk

early season with the shallow snow pack and clear cool temperatures existing for a period of time, instabilities

existed in the form of a faceted layer. this provided the failure for the avalanche incident. during the winter most significant weakness in the snow pack existed during storm cycles as wind and temperatures changed. any instability that existed during the storm settled quickly with warmer weather patterns following. the most significant affect on the snow pack this past season was the lack of consistent snowfall and with the couple of reasonable snow falls received, rain seem to follow within a week or so. 1 to 1.5m of snow still exists on the upper mountain above 1600m with spring time conditions being firm at first and softening during the day on sunny aspects.

CoNCLuSioN

it has not been the greatest of winters for snow or skiing on mt taranaki, the reason being the weather has been too nice. this has provided some great weather days to enjoy our amazing playground. what surprised me this winter after having a near fatal avalanche incident on the mountain, was the attendance at the local avalanche awareness course (5 people). despite best efforts from several people to garner interest, participation was still low. i would have thought that people might have embraced the opportunity to upskill their mountain knowledge, but unfortunately this year it was not to be.

what was pleasing to see was the patience by the ski area users on powder days. Part of the area was closed off due to a significant weak layer 40cm down. this was done to allow things to settle out and reopened the following day for some great turns. well done skiers and boarders. it seems that over the past few years the safety message is getting out there, but to how many in the taranaki region?

mt taranaki is a hard mountain to forecast for at times with interesting terrain features and snow conditions. with my time in the snow industry i find myself taking some long hard looks at conditions, and i always wonder how other people just blindly walk off into the backcountry, do they not consider how their decisions will affect their family and friends?

although the attitudes of some are improving we need to consistently highlight the dangers for all mountain users and educate the public. we all love the outdoors and need to go home to loved ones with richer safer experiences. ▲

TaraNaKi // TOdd CaTiONS-vELviN

oVErViEW

another winter has come and gone in what seems to be in the blink of an eye - promising signs came and went followed by the donning of singlets and shorts. mt taranaki saw its first recorded avalanche involvement just as winter was kicking off, highlighting the dangers of alpine travel. in brief here is a summary of winter 2012.




WEAThEr

this winter started in the first week of June with the largest snow fall to low elevations since this forecast began four years ago. this was prior to avalanche forecasting starting for the winter season. i flew over the park on June 7 and there was plenty of evidence of avalanche activity on eastern aspects with a size three appearing to have been set off by a chamois with tracks going in but not coming out.

unfortunately this was followed by a long period of non-snow producing Ne winds and cloud lasting for three weeks during July. warm rain dominated and significant ablation occurred during this time. one fall on July 20 was 127mm, with a further 19mm on July 30. there was intermittent rain or snow above 1800m during this time. the snow drought was not significantly broken until mid-august when 30 to 50 cm of snow fell between the 12-16 august. unfortunately the rain returned on august 20, with 15mm creating a melt freeze crust and then snow fell over this, creating the only persistent weakness in the snow pack during the season.

the second largest snow fall of the winter fell on 8-9 of September, with substantial snow fall down to valley floor. up to 1m was recorded at Blue lakes hut. further small snow falls and rain have continued intermittently until the start of october and this pattern seems set to continue for a while yet. this winter has had few long settled periods.

SNoWPACk

the majority of the early snow pack fell in the first week of June. most of the snow from this and subsequent storms has been deposited on easterly half aspects. due to the depth of the initial snow, the moderate air temperatures and occasional large rain storms to high elevation, there has been very little evidence of faceting at any stage.

as a consequence the majority of the avalanches cycles have occurred within the new snow during storms, or due to loose, wet avalanches caused by solar radiation and rain events. once the initial storm snow that fell in June settled out, it produced no significant weaknesses. this was then saturated in July by a substantial rain event and warm

ambient air temperatures over a number of weeks. the snow was comprised of wet grains in a sometimes frozen but most often unfrozen state for the majority of July. the snow pack was weak when unfrozen.

august snows and cooler temperatures caused layers of small strong well sintered rounds to be deposited over the refrozen early snowpack. this was capped with a rain crust on august 20 which was then loaded with further snow. this rain crust appeared initially to be problematic with easy clean shear and compression failures just below the crust. despite it persisting for a week little avalanche activity was seen. over September 8 and 9, 100 – 150cm of wind affected snow was deposited onto easterly aspects. during this storm both the freezing level and humidity rose and produced very unstable conditions for a 36 hour period. fracture line profiles showed low density new snow capped by a higher density layer. this instability settled rapidly. the progression back to a spring snow pack occurred during the rest of the month. eastern aspects developed substantial glide cracks during this time many of which have intermittently produced avalanche activity. the winter will be remembered for very little facet development and a warm July.

AVALANChE ACTiViTy

it is believed that the first substantial avalanche cycle occurred during the early June storm prior to this forecasting program having started. the events witnessed from the air were on eastern aspects, size 2 to 3 and numerous in number.

wet snow avalanche activity dominated July, mainly due to rain with the largest cycle occurring on the 20 July caused by 127mm of rain to high elevations. Some small wind slab avalanches were produced by the august 12-16 storm. due to the slow precipitation rates and lower wind speeds these were mainly small, isolated to ridge crest and settled quickly after the storm. the largest avalanche cycle of the forecasting season occurred on September 8-9. this was caused by a density inversion within the new snow and produced size 2 to 3.5 avalanches on eastern aspects >>

NELSON LaKES NaTiONaL parK // maTT wiLKiNSON

oVErViEW

this is the fourth winter of the Back country avalanche advisory in the Nelson lakes National Park. the programme is now well supported by four different web cams, two automated weather telemetry stations and observations by both the rainbow Ski Patrol and department of conservation (doc) personnel.

the opportunity to see the park from the air is common due to the support by doc and the avalanche forecaster often working with the Nelson marlborough rescue helicopter. the continued support of both doc and the rainbow Ski area has seen the programme become an important part of the safety management for winter visitors to Nelson lakes National Park.




many of which were able to reach valley floor. loose snow avalanches have continued until the time of writing. extensive glide cracks developed on eastern aspects below 1800m during the latter part of September. this has produced reasonably extensive avalanche activity on mid slope rollovers, the timing of which has been difficult to pin down.

TrAVEL ADViSory

Substantial snow cover on eastern half aspects will continue to see increasing avalanche danger during times of warm air temperatures and high solar radiation. rain and warm temperatures will also accelerate snowpack creep and glide which will see a continuation in ground release wet slabs during spring that have been observed during late September. caution will be required on solar aspects during the afternoon when air temperatures are high and during rain when the snowpack becomes unsupportive on skis or while walking. it will be important for people walking in the valleys to remember that there is still significant snow in the basins above. most caution will need to be exercised during intense rainfall to high elevation.

CoNCLuDiNg rEMArkS

this advisory will again continue until there has been a significant decrease in total snow cover. this is due to the continued support from the department of conservation. there is still good snow cover in a lot of the high places within the park so spring missions are definitely worth planning for. i would again like to thank N.i.w.a. for the remote access to weather information. i would especially like to thank rainbow Ski areas continued support of the program, in particular adrian Briggs the Ski Patrol manager. ▲

Avalanche awareness, advisories & info


WEAThEr

July was warm and calm the first half of the month. with the warm temps, light winds, and no snow, the snow pack was greatly affected. July 21 brought over 300mm of rain in the following four days. a period of high pressure with partly cloudy skies and some fog rolled through, but the last day of the month brought rain, snow up high and gale force winds from the east/So-east.

august brought ~100mm of rain with some small snow storms scattered among mostly fine days. the 13th was the biggest accumulation day since early June with ~20cm hitting the zone from a Se with moderate to strong winds. again warm temps and mostly clear weather greatly reduced the snowpack, though there were plenty of days when the clouds didn’t let the sun in. rain late in the month destroyed the pack once again to ~1600m.

By September, the majority of the snow below 1600m had melted or been rinsed away by rain. on September 2 another heavy rain storm moved in with gale force winds gusting over 120kph from the Nw. Between the 2-16 September over 400mm of precipitation had fallen with snow starting day 9 and continuing to day 17. the rain/snow line stayed in a state of flux with periods of heavy rain falling as well. over a meter fell above 1300m, making the zone look like winter again. a calm warm period followed until the 25 September with light rains returning from the N bringing ~15cm of snow above 1600m. the month ended with warm temperatures, clear skies and a sky rocketing freezing level of 3600m.

SNoWPACk

the storm in early June set down a nice base and by the time observers set up shop the stability was good in the alpine and high alpine with small isolated pockets of wind slab that remained from the last storm. heavy rains late in July rinsed away the majority of the snowpack below 1600m. as the high pressure took hold the snowpack settled into a regular melt-freeze cycle and the warm temperatures were slowly eating away the pack. Bursts of precipitation and wind would add load to the pack as rain below ~1600m and snow above. Small wind slabs would build on the lee aspects, but would quickly break down in the following heat. every rain event was like hitting a “reset” button, as the snowpack would refreeze back into a nearly impenetrable block of ice.

September brought more rain and wind with snow accumulations up to 4m on lee slopes above 1500m. this new loaded bonded quickly and became heat affected, bringing a short period of natural shedding. the widespread instabilities that were experienced were temperature influenced. wet slides were the majority of the danger due to the weather, whereas the wind slabs and storm snow instabilities quickly settled out.

AVALANChE ACTiViTy

wet slides dominated the activity type, with many loose wet slides occurring throughout the season. many of these were smaller than size 1.5, but some slides in the mingha valley, mt. Philistine and mt. Phipps regions were up to size 2. the Bealey face of mt. rolleston saw a large size 3 slide during the July 21 rain event. during the September 9storm a size 4-5 was reported in the off of Goldney ridge on mt. rolleston, but evidence was hard to see during the storm and by the time visibility had improved the debris would suggest a slide closer to size 3-4. the rain and warm temperatures were the driving factors in the avalanche cycles the entire season.

CoNCLuDiNg rEMArkS

heavy rains and low snow totals made for a difficult season in the arthur’s Pass area. above 1600m good skiing could be found with the proper amount of effort, and stability was generally fair to good once the weather cleared. although, the low snow totals presented another set of hazards. Ground hazards littered pitches and turned runout zones into mine fields. frozen, slick surface conditions deterred skiers and rewarded climbers. the atypical conditions changed the way people needed to travel in the backcountry and how we as professionals (inside and out of the ski field) do our jobs effectively.

i would like to briefly thank everyone at temple Basin Ski club for a great season, regardless of the weather and for helping out me out as the foreigner. andrew hobman and Gordie Smith for great feedback all season and Jason Konigsberg and elliot James for holding down the fort after i left. thanks again and see you next season. ▲

arThur’S paSS NaTiONaL parK // drEw GiBSON

oVErViEW

the 2012 season was a wet one. heavy rains pounded the divide throughout the season, keeping the snow line around 1600m-1700m. the two largest snow falls occurred in early June and mid-September, but the in-between was dominated by rain.




WEAThEr

June’s early snow fall of 1-2m transformed the range from summer to winter over 12hrs and raised hope of big things to come. this season saw the region’s weather dominated by a wave of easterly systems. these easterlies saw a number of consecutive riming events and blocked the sun for days on end. these patterns are generally unusual for canterbury. as a result the range was left looking very different to normal years with loading in areas that do not normally see a lot of snow. Settled weather generally persisted, with spring like conditions throughout July and august. we pushed through a number of significant rain events which saw the snow pack tested on several occasions. the wind that we battle on a somewhat regular basis didn’t not turn up until early September, but the north west system that saw most of the ski areas close for up to a week made up for the lack of wind during the bulk of the season.

SNoWPACk

rain events, warm temps and long dry spells set the scene for a generally well bonded and stable snow pack and favourable touring conditions. July’s snow fall of less than 10cm along with cold clear nights saw a continental snow pack set up along the range. the rain that fell in large volumes on several occasions over the winter never seem to be followed up by wide spread avalanche cycles. this was due to the high rain totals percolating through the pack to ground rather than stopping half way down and lubricating one of the several crusts that could be found. Near surface facets were producing some interesting test results throughout august/September. october brought a top heavy snow pack with more new snow and some of the strongest winds of the year recorded. Spring hit quickly with melt freeze conditions, isothermic snow along with more rain and freezing levels 1000m above ridge line.

AVALANChE ACTiViTy

avalanches along the range were mostly limited to wet snow issues for the duration of the season. Notable exceptions to this were some large events during the June 5 storm, where naturally-triggered wind slabs up to size 3.5, damaged lifts and buildings at local ski areas. July saw more rain and events up to size 2.5 running out the easterly quarter.

the snow pack was again reactive on 15 august after a light snowfall and intense green housing during the day. Simply rolling a snowball triggered up to size 2.5 wet slides running full path from ridge top on westerly aspects. these conditions lead to a natural wide spread avalanche cycle along the range.

CoNCLuDiNg rEMArkS

this season has produced some great touring opportunities along the craigieburns. we experienced generally stable conditions and good coverage above 1400m for the majority of the winter. there are still a lot of individuals heading into the back country without the appropriate gear or knowledge. this issue continues to be a major concern. thanks to all those out there who have provided information and observations over the course of the winter. ▲

CraiGiEBurNS // davE LuNdiN

oVErViEW

the 2012 winter in the craigieburns went from zero to hero with a North american style storm in early June. we have unfortunately seen another low snowfall year with spring-like conditions dominating for much of the season. we experienced long periods of dry warm weather which made for generally stable conditions. coverage along the range saw a reverse from the 2011 season, with minimal coverage below 1400m making running shoes an essential piece of kit for getting out of the hills.




WEAThEr

the season started when a big Se snowfall in the canterbury region around June 8 had 30cm of snow in methven with more at higher elevations making a great start to the season. from there we continued to get the easterly weather pattern over the season with regular top ups of snow. many of the storms started very warm with high freezing levels producing rain that would then turn to snow in the later part of the storm. one of the storms in later July stayed warm causing some great unusual corn snow in July.

variance in precipitation amounts and temperatures showed in the total amounts of snow; one storm resulted in mt dobson receiving 120cm of snow while mt hutt received 40cm, while further to the divide not far from hutt (Palmers) 100cm of snow was observed. rime crusts also varied with some areas getting heavy crust at the end of storms while others were left with light snow surfaces. when the storms finally cleared it was generally cold which helped keep snow conditions good for days after snowfalls.

a strong/gale Nw storm in September closed mt hutt for 5 consecutive days and many think this may be the longest closed period ever (or at least in memory of many old timers), while in the arrowsmiths during that same storm we stopped recording estimated snow depth when it hit 2m with precipitation rates of over 25mm per hr.

SNoWPACk

the season started with a major snowfall June 8, with 80cm at 700m in the high country stations and 60cm at mt hutt. a period of fine weather following the storm helped facet growth but this never became a problem with the high freezing levels at the start of the following storms. rain drainage channels in the snowpack were established early in the season and as a number of storms produced rain early in the storm cycle it was quickly dispersed onto the ground and away causing only rain on dry snow issues (loose snow avalanches rather than slabs).

large surface hoar (up to 10mm) was observed on a number of occasions during the season due to the easterly cloud hanging around against the hills. again this never became an issue with either wind or rain destroying the surface hoar before it was buried.

lower elevations overall had less snow for a majority of the season, with the snow line sitting around the 1400m mark, the exception being June with snow in methven.in the eastern part of the range the easterly weather pattern produced rime/rain at the end of the storms leaving crusts up to 2cm thick at times. the best time for skiing was in the middle of the storm before the rime struck on the clearing pattern. these crusts did produce avalanches in the following storm cycles.

AVALANChE ACTiViTy

an unusual event of June was a natural avalanche cycle on the road to Glenfalloch Station early in the season, the same storm that produced snow in methven. the local trucking company called methven heliski to ask advice on safety getting up the road to help clear the snow for farmers. the debris from these slides even stayed next to the road for about a month reminding us of the great start to the season. a natural cycle at mt hutt on aug 12 was the major storm of the season for avalanche activity in the eastern part of the range. heavy precipitation rates from the Ne caused a natural avalanche cycle lee to the Ne ¼ up to Size 2.

otherwise the usual storm snow instabilities occurred during the season up to size 2.5. late august and into September saw multiple smaller storm cycles and an increase in the winds from the Nw causing the pack further east to warm up and become stable. wet slide activity has been minimal so far this season in the mt hutt regions with many of the lower start zones below threshold from constant warm temps and high freezing levels. further to the west we have had regular wet slide cycles after any new snow on solar aspects.

further west, the usual Nw-Sw storms were a little less frequent and often the higher freezing levels of the easterly caused a widespread avalanche cycle near the start of the storm (rain on snow), which would then be covered with snow as the freezing level dropped as the storm progressed. further west we had less of the rime/rain crusts near the end of the storm that affected the areas further east. >>

arrOwSmiThS/TayLOrS/mT huTT // JamiE rOBErTSON

oVErViEW

what a great season for the mid canterbury areas with lots of easterly snow! when the weather cleared people made the most of the great conditions to get into the backcountry and enjoy some great lines. the canterbury winter response was tested this winter with a SareX off the back of mt hutt. it has been a long time coming for canterbury with some other regions holding more regular exercises. overall the response went very well and it highlighted how much we rely on the skills of the mt hutt crew for their expertise and the need for skilled, trained people on site. i hope this is just a starting point for more training in the future and better resources both north and south of the mt hutt region.




TrAVEL ADViSory

we have had less Nw-Sw storms this season which can keep the danger at high for a number of days. danger has also been much more predictable than in past years due to a lack of deeper instabilities.

the usual problems with the large east-west nature of the forecasting regions has caused the danger to be variable across the region and on the website; care is required by the reader to pick which parts of the forecast are relating to the different parts of the region.

danger levels on solar aspects stayed at high, as after eachnew snowfall we expect the solar aspects to fall downwhen the sun hits them. the new snow instabilities havestabilised quickly during most of the season and a lot ofusually un-skied lines have seen descents.

the weather this season has been a significant barrier to getting into the backcountry and timing of days to get out has been the key.

CoNCLuDiNg rEMArkS

Generally the ski touring has been very good all season with reports of people heading out from the top of mt hutt having fun, safe turns. the central arrowsmiths have seen less touring with the limited snow cover around the cameron hut perhaps influencing decisions on where to go. the snowpack for the mt hutt region is very good (160cm at present) and touring to the end of october would be a good option for those keen to get more turns in(rain dependent in the next few weeks). Snow around the cameron hut is limited and will require some keen folks walking their equipment to the snow line.

enjoy the spring, and take advantage of the good snow at higher elevations. ▲


WEAThEr

an early season fine spell ended on 13 July with a rather warm Nw storm. rain to 2600m, followed by a colder, very windy Sw change, laid down a solid rain crust capped with up to 20cm of sculptured fine grained chalky windpack. 23 July saw the first taste of easterly weather. cloud but no significant precipitation followed a bit of Nw, then on 30 July came the real deal. Strong easterlies and 78mm precipitation arrived in the village by the 2 aug, with snow to valley floor. the easterly pattern continued well into august with 30 to 50cm hSt over a few days mid month and a smaller drop on day20 bringing 5 to 20cm. westerly weather returned on day 25, with gale Nw winds and 100mm in the rain gauge with a shift to the Sw by 28 august. the westerlies persisted into September. for a while there it looked like a rough spring lay in store but the second half of the month saw good fine spells between storms that allowed some great skiing.

SNoWPACk

the season kicked off with a good stable pack. hS measured at the rose ridge weather station (1940m malte range ,murchison valley) was 2m with around 40cm at mueller hut. the first big Nw storm added a lot of weight but not much depth to the pack leaving us with a bomber (July 16) rain crust topped by a patchy 0 to 20cm of windblown Sw snow and good stability. the subsequent fine spell saw some hoar and faceting at or near the surface. Snow tests and pits following the first big easterly storm showed mostly moderate to hard resistant planar (rP) results on July crust, with the odd isolated easier result where the hoar and facets had survived. this weakness (and the mannering avalanche), led to a period of uncertainty during the easterlies, as layers were separated by light rime crusts, and sometimes surface hoar built up. the chance of another large avalanche on the day16 crust had to be considered even though snow tests on the layer were mostly positive. Quite variable results and layering in the easterly snowfalls kept the risk of smaller slabs alive until stability was finally

rated as good again on august 18t. Subsequent storms followed a more normal pattern with poor stability and avalanching during the bad weather, followed by reasonably rapid transitions through fair to good stability.

AVALANChE ACTiViTy

Some size 3 slabs on e aspects were observed to run in the hooker valley as a result of the august 13 storm, with widespread loose wet slide activity below 2300m as a result of rain. isolated slabs on N aspects with 30 cm crowns were observed in the tasman valley on august 1 during the first easterly storm. on august 6, two male skiers triggered and were carried over 200m in a shallow but wide 2.5 size slab. the second skier down triggered a small slab mid-slope that soon stepped out to either side and up to the top, catching a second person who had just moved forward to start their descent. Both men successfully deployed their airbags. debris fanned out on gentler terrain below. Skis and poles lost in the slide were recovered on the surface of the shallow debris, and witnesses believe that while a burial might have been possible, it was unlikely. a subsequent snowpit by the group showed a weakness of surface hoar and faceting in Sw snow that lay over the July 16 rain crust. this was not evident in snowpits they had dug earlier that day.

widespread loose wet slides up to size 2 ran on august 14 as a result of rapid warming in fresh easterly snow. Size3’s were seen in Stocking Stm and the hayter on 26 august. widespread size 2.5 slab activity on S/Se aspects was subsequently observed on the eastern side of the malte Brun range from the same Nw storm. Numerous slightly smaller slabs ran further east out in the liebig and Gammack ranges. another round of size 3 slabs ran 3 September during a Nw storm including an impressive event down the Nuns veil Glacier. frequent flyer Stocking Stream ran at size 3 again on September 8. this path is prone to Sw wind loading during clearing weather at the end of a storm and often runs out to well below the snowline. >>

oVErViEW

2012 was another unique but reasonably unremarkable winter. a little less precipitation than normal out of the Nw resulted in fewer large main divide avalanche cycles than we’d usually see. the easterly events early august helped to top up what would have otherwise been a thin lower elevation snowpack and there were enough cold westerly storms in spring to keep the powder in shape on shady aspects right through till the end of September.

aOraKi / mT COOK // TrEv STrEaT




September 26 saw the last significant avalanche cycle in the reporting period. it followed a Nw storm that dropped around 60mm of rain in the village with snow above about 1700m. Significant amounts of wind loading plus pre storm surface hoar on sheltered shady aspects resulted in large avalanches on the murchison headwall & Stocking stm / te waewae Glacier paths as well as several slabs on S aspects in the mannering Gl area and on the cornice wall.

alpine rescue techniques $69.95

avalanche accidents $15.00

alpine Skills $20.00

CoNCLuDiNg rEMArkS

despite a rather thin snowpack at lower elevations, the winter has left us with excellent snow cover on the neves and there will be some great touring to be had over the next month, get into it! ▲

avalanche awareness $30.00

avalanche handbook $45.00

NZ Guidelines and recording Standards for weather, Snowpack and avalanche observations (2011, NZ) $30.00

aLpiNE aNd avaLaNChE rESOurCES

avalanche assessor card $11.99

avalanche rescue card $11.99

card combo (both cards) $19.99

To purchase any of these resources online, please visit www.mountainsafety.org.nz/resources


WEAThEr

conditions were pretty benign for most of the season, it must be said. June, July and august saw only limited amounts of precipitation. the moisture-laden Nw systems which produce large quantities of rain/snow in this area failed to materialise.

most of the systems which pushed across the region were quite weak, warm Northerlies or from an easterly direction. the snow threshold hovered around the 1400m mark most of the season. winds were light to moderate and generally from the Northerly quarter or the east. the very strong winds from the Sw or South which often hit this area through the winter were noticeably absent. there were a number of periods of cold, clear weather with accompanying low temperatures.

unfortunately, there were also several spells of easterly weather which, while they produced some much needed snow also, created long periods of very poor visibility. in September, we finally enjoyed a couple of decent Nw storms with plenty of snow and gale force winds.

SNoWPACk

the snow pack remained shallow for three quarters of the season. at the end of august, it still resembled a pack that you would typically find in June or early July. Several stout rain crusts formed during the first half of the season and they were very slow to break down. in fact, they were still a cause for concern in early September. the shallow nature of the pack ensured that when we experienced periods of cold, clear weather, we also witnessed rapid facet and depth hoar development.

during the first couple of weeks of august, we endured prolonged spells of easterly weather which in turn produced widespread areas of rime crust. these thin, friable crusts were subsequently buried and lingered as weak layers for some weeks. looking back, we were fortunate that this weak, shallow pack was not subjected to the heavy snow loading that often arrives in august. had this been the case, we would certainly have witnessed widespread cycles of natural avalanches and very probably human triggered ones as well!

we finally began to enjoy substantial snowfalls from the Nw, in early September. luckily, the weak layers of rime,

facets and depth hoar had largely settled out, helped by some warmer temperatures. also, the multiple slippery rain crusts were well advanced in the process of breaking down, in most areas. although large quantities of snow fell, as the result of a series of westerly storms, it bonded well for the most part. favourable temperatures played an important role in this outcome. most of the new snow arrived warm and wet, and consequently adhered well to the old snow surface. as these storms progressed, they became colder and thus the snow on top was cold, dry and light in weight.

AVALANChE ACTiViTy

very few human-triggered avalanches were reported in the wanaka region this year and there were no full burials or serious injuries recorded. Natural wind slab avalanches were unusual as the result of the favourable combination of weather and snow conditions outlined above. Spring avalanche activity has been limited at the time of writing (beginning of october). Small (size 1) point releases are widespread on solar aspects but few larger events appear to have occurred. an important contributing factor is that many solar aspects at mid elevations have been lean on snow all season and there is simply not the mass to produce large slides.

CoNCLuDiNg rEMArkS

the significant snowfalls that occurred during September have created good spring touring conditions. in the west of the region, the peaks and ridge lines are holding solid amounts of snow due in part, to the lack of Nw gales and mild temperatures - the conditions are much better than this time last year. in the east, the thin cover is disappearing rapidly particularly on the solar faces. the Niwa climate outlook for Spring suggests that high pressure systems are likely and westerly winds are predicted to be weaker than normal - all good news. if you are planning to head out, it is important to keep a number of things in mind. remember that a return to winter conditions (wind slab avalanches) is possible at any time of the year. always take basic self rescue equipment - transceiver, shovel and probe and know how to use them. take the time to prepare, plan and gather information especially on weather and snow conditions. ▲

oVErViEW

the 2012 season in the wanaka region can be summed up as uneventful as far as avalanches are concerned. intense weather systems were rare and as a consequence, we received only limited amounts of snow particularly, in the early and middle parts of the winter. winds were generally light and temperatures relatively mild. this led to mostly stable conditions with the advisory, elevated to high on only a handful of days. happily, there were very few human triggered slides. No full burials or serious injuries were reported.

waNaKa // SimON hOwELLS




WEAThEr

compared to last season early June showed promise with temperatures cold enough for snowmaking to begin, in fact most ski areas began their season thanks to the snow guns. Ski areas that had limited snow making capacity had limited skiing.

there was the predictable late June rain event (something that did not happen last season). July remained cold, then the dreaded easterly snow pattern commenced. Storms would move down from North Queensland, dropping most of the precipitation on the North island (a very wet winter for the east coast of the North and South islands). Queenstown lakes was left with the dregs, basically moist clouds. this pattern continued in monotonous regularity. as soon as one system cleared the next almost identical one would take its place. this was the pattern for July with four system over four weeks, each depositing 5 to 15 cm around the district.

No problem august was here (or so we wished) winter powder a plenty will come. this is where Queenstown set two new winter records. there was 11 mm of rain for the month of august, the driest monthly rainfall since records began over 100 years ago. record two, Queenstown was the sunniest place in NZ for the month of august, the first time it had won the title (you guessed it) since records began.

September has been the saving grace for the powder starved. the first system deposited over 1m of snow and was quickly followed by another 80 cm fall. the pattern continued for most of the month until the last week when signs of spring corn appeared and things started to heat up.

with ski-fields set to close in october most will have their best snow-base for the season, this is a very similar story to the ‘10 season, last season was a dry spring for sure with ‘slide for life’ (cold nights and warm days)conditions common during September.

SNoWPACk

let’s face it, it was a low snow year and often in these types of seasons the snowpack can be affected by strong temperature gradients. Supportive layers weaken and the

whole pack becomes weak with poor bonding between layers. New snow then produces high to extreme avalanche conditions. we did not see this occur with this season’s snowpack, why?

Perhaps the top ups were just enough. the easterly storms brought with them an average of 5 to 10 cm’s, every week through July we would get some new snow, not much but just enough. Snow from the east is almost always rimed. Snow bonds very well and has high moisture content. the combination of very little and well bonded snow meant avalanche activity was minimal. august, well 11 mm of rain (if it wasn’t for the 8 mm on august 29 the total would have been 3 mm) tells its own story. wind was minimal for the month and temperatures although cold, were not as cold as previous years. the occasional warm day did help with consolidation. Spring has been very unsettled so the melt/freeze cycle (needed to create spring corn) was delayed. September has seen some of the best powder skiing/riding of the season. Predictions are for some great touring for the month of october.

AVALANChE ACTiViTy

Backcountry users triggered nine events in this region. of those seven, five people were caught but not fully buried, and some lost equipment. the majority of the involvements were after the late august snowfall. rapid warming in the last week of September ripened conditions for the other involvements. all but one were in terrain above 35 degrees with three of the five caught in terrain above 40 degrees.

CoNCLuDiNg rEMArkS

it just goes to show that even in a low snow year avalanche involvements are still high, remembering that these are just for the Queenstown region. the avalanche awareness courses offered by the mountain Safely council continue to be well attended. if you have yet to do a course, then set yourself a goal for next season. Get yourself skilled up by one of our professionals on how to be better prepared, and how to be safer in the backcountry, while still enjoying the experience. ▲

oVErViEW

the 2012 winter season was in some way a stark contrast to last year, in fact it was very similar to the 2010 season. however, like last year there were two new records. the season wrap up for this year, i’m afraid, will replicate a similar wrap from other South island districts, basically, a low snow year. the bulk of winter was considered abnormal, in terms of below average snowfalls, however spring has surprised us all with many calling it the start of winter. the biggest falls of the season have arrived with spring, and with it the wind. September has seen the avalanche danger at its highest setting all season, lets dig a little deeper.

QuEENSTOwN // ChriS COChraNE




TrAVEL ADViSory

writing the Backcountry advisory for fiordland felt like ground hog day, as conditions hardly changed between June 28and early September. due to the weather systems this year it was easier writing a general advisory for the park compared to last year when the snow conditions varied hugely between areas in the North and South.

most of the season sat on ‘low’ danger in the three altitude bands, with the slight rise in the higher elevations to ‘moderate’ during small snow accumulations. however, during the westerly development in early September, the advisory increased to ‘considerable’ then ‘high’, as the new storm snow caused extra stress to existing layers.

the facet layers that developed in the calm Se periods of July and august, hung around all season, but only caused a concern once we got significant snow fall. (early September).

from September 11 right through to october 1 the advisory has been sitting up on ‘considerable’ danger due to:

• persistent layers in the higher altitudes (southern facet layers).

• wet slab activity during the warming mid to late Sept, and heavy rain events.

• loose wet slides due to the solar influences and high fl.

SNoWPACk

a small snow storm late June (23- 26) covered the ground and set the bed surface for the rest of the season. a cool settled period (light snowfall to low elevations) on July 6 topped it up and started the initial layering. Below 1700m snow slowly melted away. however above 1700m light accumulations incrementally built up the snow pack. the cold clear periods allowed for facet growth in the higher

southern aspects. this didn’t cause any concern till we received significant snow in early September.

the official start of Spring brought heavy rain from the Nw (high fl) which set off wide spread wet slide activity (a handful of these were to ground). the rinsing also depleted the snow pack below 1400m. as the large system moved across the region, a turn more to the w-Sw brought snow to low levels. above 1800m over 3m of snow arrived from a strong Sw w. this extra snow caused wide spread activity.

the end of September saw a short sharp rain event soak the snow pack below 1700m, once again making lower elevation snow heavy and dense. Quietly in the higher elevations above 1700m snow has still been accumulating. in some areas the start zones are well above threshold and as we enter the Spring warm up (october) this will create some uncertainty.

AVALANChE ACTiViTy

Before the early September storm, this had been a very lean year for activity with only a few, very small avalanches releasing. these early events tended to run from glaciated bed surfaces, and lacked any particular pattern.

come early September, a widespread wet slab cycle was driven by heavy Nw rain (fl 2000m at the time). this was followed by snow to low levels. up high, new snow caused extra stress to the persistent layers (facets deep in the southern aspects). again wide spread avalanches pulled out during the second week of September due to overloading in the upper start zones. Notably, wet slabs and loose wet events occurred through the September warm up, most below size 2, pulling out from all aspects below 1700mthen the big event in mid-September saw the larger start zones pulling out (above 2000m) on the July facet layer deeper in the pack. >>

oVErViEW

thanks to the la Nina influence on weather systems this winter, fiordland became one of the driest areas in New Zealand. after a short sharp start in late June, which produced very little to no activity, the general Nw flow gave way to an easterly flow, which left fiordland unaffected. a couple of mild fronts in mid July destroyed the snow pack below 1800m. Small accumulation did gather above this, and with periods of settled weather, facets grew on the southern aspects.

it took until late august before the la Nina cycle broke. Nw’ers became dominant again. rain below 1800m created wide spread wet slides, and new snow higher up didn’t stick (constantly sluffing). Some of these smaller avalanches were enough to initiate bigger avalanches that ran from deeper persistent layers in the pack. (facets/ice crusts on southern aspects). we rely heavily on remote weather data, so it was a huge blow to lose one of our high weather stations early on (castle 2000m milford track). we suspect it got knocked out by heavy riming in late June, and is still waiting repairs.

it took until September for winter to really turn up. we received well over 3m of snow in the first few weeks which triggered some bigger avalanches (size 3-4.5) in start zones above 2000m, especially within Northern fiordland.

FiOrdLaNd // adriaN BraaKSma




CoNCLuDiNg rEMArkS

overall, fiordland was spared its more usual high precipitation levels, and left with a mild winter. Snow accumulations built up significantly during storm’s Glen, harold and Jeff, (the two weeks after September 11 ). Numbers wise, users of the park started with a hiss and a roar, with the annual alpine club’s homer hut meet in July. then numbers remained steadily low. very few ski touring parties ventured into the Keplers this winter due to insufficient snow cover.

Big thanks to downers (milford road avalanche programme) for their support, information and expertise, as well as the te anau area doc staff for sharing information and reporting observations back to base. these observations are a key element to keep advisories as accurate and timely as possible. ▲

avalanche control work – Queenstown style.

on the last control day of 2012, which fell on the very last day of the season, aaron ‘helicopter’ halsted supervises a ground team working through a hand charging route in the alta chutes. email your own caption of what you reckon he said! Best responses will be published in the next edition! email [email protected] by 30 November.

COmpETiTiON: SuppLy ThE CapTiON BELOw. JUST FORFUN!


having recently gained the Stage 2 avalanche qualification, Jane, who works in the guiding industry, shares her perspective, and busts a few myths that surround this course of study.

STAgE 2 AVALANChE: A PArTiCiPANT’S PErSPECTiVE // JANE MorriS

So you’re armed and preparing yourself for battle with the Stage 2 beast.

whoa, hang on – does it really live up to the frightening proportions the whispers of the winter underworld may have us believe?

having recently navigated this mythical war path, from my observations, there were far more allies than enemies out there if you travel with an open mind, a drive to learn, and an appreciation for all those in the environment.

In the simplest terms, there are 5 steps to the Stage 2 process:

• CALL Barbara emmitt at the cromwell Branch of the otago Polytechnic and enrol on the course.

• Do ThE ThEory PAPErS: there are three modules including rescue and mitigation, Snowpack analysis and decision making/human factors). autumn is a good time to start this as it gets you thinking about winter but there’s no snow to distract you yet.

• gET ThE MENTor SigN oFF DAyS; under four topics of terrain, rescue, snow profiling and stability forms; start this happening from when you enrol on the course.

• ATTEND ThE FiELD TrAiNiNg; a five day course currently based out of wanaka, where you’ll get an idea of where you’re at, what to work on, and a chance to hang out with a whole raft of folks from various industry backgrounds.

• CoMPLETE ThE ASSESSMENT; an eight day course also currently based out of wanaka; and although it’s an assessment, there are still teaching and learning opportunities amongst it. concerns? you’ll have plenty. Pete Bilous will ensure it.

Five tips to help you on the Stage 2 pathway:

1. ChooSE MENTorS/A ThEory SuPPorT ADViSor you CoNNECT WiTh; by this stage you’ll know a few people in the industry. think about the ones you get on with, respect, and would happily go into the backcountry with. Seek them out, offer bribes and badger them relentlessly.

2. go BACkCouNTry WiTh DiFFErENT PEoPLE; whilst you’ll have buddies you can just click and go with, make the effort to spend time with different people in the backcountry, even for one day – the learning opportunities are fantastic. >>


5. ENJoy ThE JourNEy; remind yourself why you are doing this….and that it is a choice. the only battle is the one with yourself.

it’s all about learning, and Stage 2 lays a solid foundation from which all subsequent learning, i believe, has more relevance and application. embrace it.

if we collectively think of Stage 2 as a positive pathway and support those who are undertaking it, then it will be a win-win for all involved.

i see it as a very valuable process, with every part feeding into the bigger picture of doing all we can to educate ourselves in the ongoing continuum of having safe and happy experiences in the mountains. ▲

acknowledgements

Thanks to all those who’ve given me mentoring and support on my pathway:

Bill Atkinson, Mark Austin, Pete Bilous, Kevin Boekholt, Jef Desbecker, Dave

McKinley, Tarn Pilkington, Remarks Patrol (in particular Matt Chessor, Jono

Gillan), Rich Raynes, Scully Redwood, Jamie Robertson, Davie Robinson,

Gordon Smith, Roy Smith, and all the 2012 Stage 2 participants – Mark

Brown, Callum Grant, Michel LePage, Mike Madden, Ronan Maguire, Gordon

Menzies, Mike Lundin, Scott Walker.

more pictures can be seen here

3. gET ouT iN ThE WEAThEr; you’ll learn far more about your decision-making, your systems and how your gear performs when the wind is pulverising your brain, and you’re wondering where the windscreen wiper switch is on your goggles.

4. BE ProACTiVE; the learning doesn’t arrive in a pile of debris at your doorstep. dig around, make time to have face-to-face discussions with people, be ruthless with collecting your paperwork and do all you can to make it as easy as possible for the people mentoring you.

http://www.facebook.com/media/set/?set=a.469657836412527.111968.203013576410289&type=3


abstract: Search theory was developed by the uSa during world war 2 Koopman (1946, 1980) to make hunting for submarines more effective. its key concepts of; effective Search width, effort, Probability of area, Probability of Success and Probability density are applicable to avalanche rescue. By combining the search theory concepts with likely burial survival times it is possible to forecast the likely probability of a live find in an area in the debris, if a particular technique is applied at a point in time with a certain level of resources. the coordinated incident management system (cimS) is the incident management system that has been adopted in New Zealand. utilising the search theory concepts and the principles of cimS at large scale avalanche rescue responses should lead to an increased likelihood of live finds.

appLyiNG SEarCh ThEOry aNd COOrdiNaTEd iNCidENT maNaGEmENT TO avaLaNChE rESCuE // dON BOGiE¹* & aNdrEw hOBmaN²

1. iNTroDuCTioN

Search theory was developed during world war 2 by the united States Navy for finding enemy submarines. Koopman (1946, 1980) use of search theory made the searching resources more effective at their search tasks. Search theory contains a number of key concepts, all of which are applicable to avalanche rescue. By incorporating probable avalanche victim survival times it is possible to forecast the probability of a live find for different techniques. cimS is a standardised way of managing incidents. at its core are seven principles. applying these principles should improve effectiveness and aid the application of the search theory concepts. as the underlying goal of avalanche rescue should be maximising live finds all search actions taken should be trying to achieve that goal.

2. kEy SEArCh ThEory CoNCEPTS

2.1 POA – Probability of Area

this is how likely is it that the search object is in the place being searched. Poa is best arrived at by consensus between a number of knowledgeable experts. it is done by splitting the debris to be searched into a number of areas that are likely to have a similar level of probability through out them. they then have a percentage likelihood assigned. the most important feature of these areas is that the likelihoods assigned must be proportional.

that is if the consensus is that one place is twice as likely as another that this is reflected in the Poa. the probability areas can then be split up into searchable segments and assigned to searchers. when this is done each segment contains a proportional amount of the Poa based on the size of the area. for instance if an area with 60% is split into 3 equal sized segments then each will have a Poa of 20%.

2.2 Pden – Probability Density

this is how likely is a unit of area to contain the search object. a small area with a moderate Poa can have a higher Pden than a larger area with higher Poa. Searching areas of higher Pden first can optimise the use of limited resources.

terrain traps are examples of places with high Pden. Pden = Poa ÷ area.

in the example in figure 1 the debris is split into three areas and assigned proportional likelihoods based on the information available. a is 9 times more likely than B and 3 times more likely than c. c is 3 times more likely than B. this then produces the Poa. Pden is derived by dividing Poa by area. the importance of the Pden is its comparative size. in the example above this means that the chances of finding the search object in c is 1.33 times more likely per m2 than in a even though its Poa is only a third of a.

if the areas are then segmented into searchable segments Poa is split across them in proportion to their size. Poa of a segment equals its Pden times its area in m². >>

figure 1: an example of a rescue site that has been split into areas by probability then segmented for searching..


2.3 ESW – Effective Sweep Width

this is the measure of the detection potential for a resource. it is the width that a search system (probe, transceiver, etc) is effective to for finding the search objects in its search path. eSw is not the maximum range of the search resource. it can be made up of a variety of ranges of effectiveness. for instance a transceiver might be able to find everything within a 20 m sweep width and 75% of things between 20 m and 30 m sweep widths and 25 % of things between 30 m and 40 m sweep width and nothing beyond a 40 m sweep width. its eSw would be 30 m as that is the range where it finds as many things beyond that range as it misses inside it. Quincy robe, frost (2002)

2.6 Effort

this is the speed times the time a resource is searching.

2.4 POD – Probability of Detection

this is how effective is the search technique? it is made up of a combination of effective sweep width and effort. Pod = eSw x effort.

2.5 POS – Probability of Success

this is how likely is the search object to be found? PoS = Poa x Pod. PoS is cumulative. as successive searches are done of a segment more and more PoS is extracted from the Poa of that segment.

3. AVALANChE SPECiFiC CoNCEPTS

there are two further concepts that are in addition to the standard search theory concepts.

3.1 POL – Probability of life

Pol is the probability that someone is still alive after a period of time buried. New Zealand has adopted a generic burial survival model for use in rescue planning. as there is no comprehensive New Zealand data on burial survival times a mixture of the european and canadian survival curves haegli, falk, Brugger, etter, Boyd (2011) has been used to give search managers guidance on possible survival times and the four key phases of a burial.

while it is possible that the chart in figure 2 indicates higher survival times than may exist in New Zealand’s maritime climate it does give incident controllers, rescuers and search planners some context for their actions. it emphasises the behaviours needed to get the best possible outcome; the need for urgent action by those on site during the first two periods, the potential for external rescuers to make a difference if they can get on site fast enough and the need to continue till the last victim is found.

Pol needs working out by taking the time since the avalanche plus the search time for the place of interest plus the likely digging time. this gives the total probable burial time that can be used to give the Pol estimate either by using the graph or a table with the Pol times in it or a search calculation app.

3.2 POLF – Probability of Live Find

this is how likely is a live find if a particular technique with a defined amount of effort is used starting from a particular point in time. PoS x Pol = Polf

4. guiDANCE NoT ABSoLuTE

it must be emphasised that the Pol and therefore Polf are guidance concepts for search planning. individual survival times in an actual event will vary with the circumstances, particularly with things like the likelihood of trauma and the snow density. the following examples show the likely influence of snow density.

this debris in figure 3 from a size 2 avalanche on mt ruapehu has a large number of interconnected small air pockets. No one was buried in this avalanche but if someone had of been it would seem highly likely that they would have survived for a long time. mt ruapehu is well known for its maritime snowpack and dense snow. the assumption would have been that any avalanche there would produce low survival times. >>

figure 2: the Pol chart, distributed by NZSar. this is used for avalanche rescue planning in New Zealand. the stripped blue lines indicate that the change from the latent 3rd period to the final period occurs somewhere in that time zone.

figure 3: Blocky debris with air gaps. Photo taken 1 hour after the avalanche occurred.


the debris in figure 4 is from an avalanche incident in the ragged range in the Southern alps, where at the time of the event the snow that avalanched was of low density (by New Zealand standards). despite a very fast rescue of less than 10 minutes the victim died of suffocation. the debris was very tightly packed fine grains.

rescuer observations of the debris characteristics of the event should therefore be taken into account when predicting possible survival times.

5. CoVErAgE AND PoD

Koopman produced the coverage versus Pod exponential model which is shown on the right hand curve on figure 5. he showed that random searching produced Pod which depended on how much coverage (eSw x effort) that searching would produce. enough random search effort to have covered the area twice produced a Pod of around 85%.

the line to the left on figure 5 is what can be achieved through systematic parallel sweeps that does not leave any gaps or do any overlaps. the reality for searchers is that producing 100% coverage with no gaps or overlaps is not possible when searching on avalanche debris. this means that some places will get searched more than once which will increase the time it takes to get 100% coverage or places will get missed which will lower the coverage amount if searchers think they have done enough effort for 100% coverage. the implication for searchers is that efforts to avoid gaps in searching can slow the resource down and most likely produce overlaps which can be wasted effort.

the effect of this is shown in figure 6. the four curves represent a single transceiver searcher searching 4 ha, 2 ha, 1 ha and 0.5 ha of debris with sweep widths from 20 m to 60 m. if 5 minutes was allowed for digging, the searcher travelled at 3 kph, had a transceiver with an eSw of 30 m and started immediately after the event the curves show the possible Polf. altering any of these variables will produce different curves. with the 0.5, 1 and 2 ha debris the maximum Polf is derived from using the eSw. for the 4 ha area maximum Polf is derived from increasing the sweep width which lowers Pod but means that the area is searched faster. with the 0.5 and 1 ha areas if the searcher errs on the side of narrow sweeps a better Polf is achieved than erring on the wider side of the eSw. with the 2 and 4 ha areas erring on the side of larger sweep width produces a higher Polf than erring on the side of tighter sweep width.

Knowing the eSw of a resource is a critical factor. there is not a lot of good information on this available. information is nearly entirely lacking with visual search and in the case of transceivers the information is often misleading as maximum range is what is usually promoted by manufacturers.

Being able to mark where searching has occurred is needed to be effective when dealing with larger sites. >>

figure 4: debris with no air gap. the rod is a 2 m long ruler. this photo was taken the day after the incident.

figure 5: comparison of random and systematic coverage.

figure 6: comparison of the effect of different transceiver sweep widths on different sizes of debris.


6. ProDuCiNg ThE grEATEST PoS For LEAST AMouNT oF EFForT

there is a fixed amount of PoS in each segment. Search effort needs to be directed at the places that PoS can be maximised. that is the greatest PoS for the least effort. PoS is like the beer in a stein, when you remove some it is gone. you can only get more added if new clues indicate higher Poa. when this happens other areas need their Poa adjusted as well so the same overall amount remains. if you search without finding anything then the amount of PoS (Poa x Pod) needs to be deducted from the segments Poa for the next set of calculations. for example if you had two segments of equal effort to search, S1 with 80% Poa and S2 with 20% Poa and if the search technique had a Pod of 65% then it would take two passes of the 80% segment with no results to get the Poa of S1 down to below the level of S2.

PoS = Poa of 80% x Pod of 65% = 52%. Starting Poa of 80% - 52% becomes a new Poa of 28%. 28% x 65% = 18% 28% - 18% = 10%

after two unsuccessful searches of S1 its Poa is now 10% and S2 is 20%. as the effort to search them is equal more PoS can be extracted from S2 with the next search pass than from S1 so S2 is now the best place to search.

7. APPLyiNg CiMS To AVALANChE rESCuE

New Zealand has adopted the coordinated incident management System cimS. ministry of civil defence and emergency management. (2005).this is very closely modelled on the North american icS. to get the maximum effectiveness from large numbers of rescuers rapidly arriving on site and to make the best use of search theory the cimS principles need applying and a large amount of control applied to the resources.

7.1 CIMS principles

cimS has the following principles:

• common terminology

• a modular organisation

• integrated communications

• consolidated incident action plans

• manageable span of control

• designated incident facilities

• comprehensive resource management

7.2 Using CIMS

at times there is a counter intuitiveness of applying a high degree of control. it may seem that time is being used to manage things rather than do things. the reflex tasking that companion rescuers apply so effectively to their responses can produce a whole range of resource use effectiveness issues if applied to large scale incidents.

observations at large scale avalanche rescue exercises that had rescuers arriving by multiple helicopters all within a short time frame showed that what would have been effective strategies for companion rescue produced reduced

effectiveness. control broke down, essential equipment got left in places where it was not accessible, some places got multiple searches done of them prior to other just as likely places getting searched. the multiple searching occurred through two reasons, the aSc tasking more resources to search with out the new resources knowing what had already been searched and self tasking rescuers deciding to do some searching of previously searched places. while the desire to do everything as fast as possible particularly when still inside the first 3 phases of the victim survival curve is highly desirable too much self tasking even by highly skilled practitioners is likely to lead to overall lesser results.

applying the search theory concepts to the management of a large avalanche rescue site shows that if rescuers arrive within the first 35 minutes allowing some of the initial responders to self task using good companion rescue skills will increase the probability of live finds. this is because any effort applied within the critical high Pol early periods yields relatively high Polf compared to more organised effort applied during lower Pol periods later on. however as more rescuers arrive the overall effectiveness of the search will decrease unless control is established and appropriate tasks assigned. this is because there is likely to be excessive coverage of some places and gaps in others. if rescuers can get on site during the 3rd victim survival phase (latent period) it is important to attempt to search all likely places in an effective manner before the drop off into the limited survival phase. to make the best use of resources it will be important to mark where previous effort has occurred to limit wasted effort.

avalanche Site commanders (aSc) need to ensure that their component of the operation has the following attributes so that they can apply cimS principles:

• a manageable span of control, so that they can mange the resources effectively and have space to think ahead.

• designated entry and equipment storage points, so all incoming resources can receive appropriate briefings and so important equipment is accessible.

• rescuer taskings-briefings, so that all resources are aware of everything they need to be aware of and are given tasks that makes them effective. it also assists with recording who is on site to help mange site safety..

• Good information on incoming resources, so that decisions can be made based on what will be on site within the near future rather than just based on what is there now.

• Places searched and all items of interest marked, so that search effort can be applied effectively.

8. CoNCLuSioN AND kEy PoiNTS

in order to achieve the goal of maximising live finds there is a need to make the most effective use of the resources. the search theory concepts and cimS principles will assist with meeting that goal. while it may not be possible to do the calculations on site during the early stages of an event the concepts should still be used to guide actions on site. Search theory can be used for good effect >>


when planning for incident responses and when assessing the effectiveness of different strategies or when developing new techniques or looking at variables with them. Search theory including doing the calculations should be used for effective management of resources during a prolonged incident and can be a key input into decisions on whether to stop searching.

8.1 kEy PoiNTS

• applying Search theory increases effectiveness

• understanding search theory concepts is important for avalanche rescue

• eSw, Polf and diminishing Poa as PoS is extracted are key concepts

• use search theory when pre planning and testing new techniques

• applying cimS principles increases effectiveness

• Need people on site who know how to manage organised rescue

• Need good information flow to aSc

while a lot of effort goes into medical equipment and expertise, transceivers, dogs and helicopters it is important to recognise that a significant contributor to the effectiveness of a major avalanche rescue site is having a large number of colour coded marker wands available on site.

9. FurThEr Work NEEDED

to get greater value out of search theory in avalanche rescue there is a need to establish more accurate effective sweep width information for the techniques being used. this is particularly important for visual search where there is no established effective sweep width information. ▲

don Bogie¹* and andrew hobman²

¹department of conservation, christchurch, New Zealand

²New Zealand mountain Safety council, christchurch, New Zealand

*corresponding author address: don Bogie, department of conservation, christchurch, New Zealand; tel +6427 2416261; email: [email protected]

acknowledgments

cooper, d. c., frost, J. r., Quincy robe, r., 2003. Compatibility of LandSAR Procedures with Search Theory. u. S. department of homeland Security united States coast Guard operations. washington, d.c.

haegeli, P., falk, m., Brugger, h., etter, hJ,. Boyd, J., 2011. Comparison of avalanche survival patterns in Canada and Switzerland. canadian medical association Journal.

Koopman, B. o. 1946. Search and Screening (OEG report No. 56). alexandria, va, centre for Naval analysis.

Koopman, B. o. 1980. Search and Screening, General Principles with Historical Applications. revised New york, Ny. Pergamon Press.

ministry of civil defence and emergency management. 2005. The New Zealand Coordinated Incident Management System (CIMS). wellington. New Zealand.

Quincy robe, r., frost, J. r., 2002. A Method for Determining Effective Sweep Widths for Land Searches. National Search and rescue committee. washington. d.c.

$35RRP

FirST aid SKiLLS FOr ThE NEw zEaLaNd OuTdOOrSoutdoor first aidNEW ZEaLaNd

the New Zealand outdoor first aid manual contains essential information about how to handle first aid and medical emergencies in New Zealand’s outdoors.this manual is suitable for all outdoor enthusiasts, but especially useful for those leading groups in the outdoors. learn how to manage a variety of scenarios and deal with any incidents that might occur, confidently and effectively.

available from all good bookshops, your local mSc branch or order online at: www.mountainsafety.org.nz/resources


31 m

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The New Zealand Mountain Safety Council invites the avalanche sector - from senior management to frontline practitioners, to the bi-annual Southern Hemisphere Avalanche Conference.

The Conference consists of a full day of workshops for the SAR sector, instructors and forecasters, followed by a two day conference of informative presentations from New Zealand and international experts on the latest developments and current best practice in theory and research, management and mitigation and search and rescue.

Take the opportunity to meet, learn and share with the best minds in the industry, trial the latest gadgets and new technology, catch-up with friends and colleagues. Registrations open soon.

If you would like to present at, or sponsor the conference please contact Andrew Hobman email [email protected] or telephone +64 27 446 2626Expressions of interest for a presentation topic deadline is November 30, 2012.

CHRISTCHURCH, NEW ZEALAND

Supported by:


richard teua is Snow Safety officer at turoa Ski area. in this article he describes his team’s response to the backcountry events that took place in early august.

ruapEhu’S avaLaNChE hOT hOuSE // By riChard TEua

turoa’s location and geography plants it smack bang in the runout zone of several very large avalanche paths with similar avalanche path dynamics flanking its boundaries. this problem has hung like an executioner’s axe over every forecaster that has ever worked at turoa, prematurely greying the hair of some and promoting the loss in others!

turoa was a late starter compared to other New Zealand ski areas. the opening of the upper slopes was during the 1978 winter. the early forecasters did not have a lot of historical data for reference, but nonetheless were quick to identify the potential avalanche danger, and come up with solutions. what has always been on our side is a maritime snowpack which settles out generally within 24hrs. ruapehu rime can also help with new snow instabilities. however one thing you can rely on when dealing with nature is it will always throw you a curve ball.

it wasn’t until a significant and unforgettable avalanche cycle during September 2003 that we became fully aware of the potential ‘dragon’ we were dealing with. threeexplosive delivery options exist to mitigate the hazards in regard to our upper mountain slide paths - hiking with case charges, helicopter bombing, and now an avalauncher.

the addition of the avalauncher gave us the option to test at will, turoa’s nemesis ‘upper Big Bowl’. during normal snow accumulation years these paths quickly become self supporting early in the winter, and control results are mostly in the d2 range or smaller. hS was just over 1 meter at 2000m in august which is not a lot of snow for this time of the year at this location.

this year has been unusual, with a persistent easterly flow early on, which i felt was a result of a lingering la Nina moving to neutral. these conditions were giving us low

volume snow falls but enough for these upper paths to reach threshold. during early July we saw these start zones looking extremely ominous with high slope angles and upper Big Bowl looking like a massive catcher’s mitt.

then in mid-July we had a rain event followed by riming at the end of the month, leaving a smooth hard snow surface. once buried the bonding would be poor under any new snow from the Northerly direction or even worse, a North

easterly. the snow came on august 3 and fell at a rate of S1 for most of the day with light winds from the Sw. that night, and on august 4 it continued to snow with light changeable winds. avalanche control work was done in the morning with a focus on the upper elevations, including upper Big bowl and Slider throat, a section of slope that would create problems the following day. Both were black holes but other slide paths were pulling out.

Bonding below 2000m was strong within the new snow with results being size ones or black holes. above 2000m results were up to size 2.5 over a variety of aspects. this reflected the changeable wind directions during the past 24hrs. the snow that fell on august 4 was of low density and then transported by a light ‘e’Se’Ne and finally winds from the north with a foot pen of 20cm at 2000m. the end result was a density inversion within large deposits on many aspects, which were 25-40cm in depth.

on august 5 it was noted that the snow temperatures were on the colder side for turoa, with a moderate near surface gradient. it was forecast for fine and clear weather conditions, with a ridge of high pressure, which resulted in a direct radiation impact during the morning. >>

above: Paritetaitonga, cloud density filtered, trapped and intensified radiation. from start zone to terminus, 500 meters in length.


the snowpack had already been affected by radiation when at midday, a light cloud rolled in from the west, creating a hot house effect.

this in turn shocked the upper layers of the snowpack adding weight and stressing the pre existing weaknesses within the top 40cm. all that was required now was a trigger. the triggers for these events were most likely rapid warming with rime failure from the upper mountain cliff bands being the primary trigger. it was rumoured that the Paritetaitonga event may have been triggered by a group of climbers but this has never been confirmed.

this particular event stood out. in thirty-odd years of working and playing in this region, i have never seen any avalanche activity on this slope. over the last thirty years the number of people using the backcountry around turoa has increased at least three-fold. within a few hours from a large population centres you can be in some pretty serious alpine terrain, in this respect we are in a similar situation to taranaki. the challenge we are all faced with is to make sure that the level of avalanche awareness amongst these increasing numbers continues to advance.

two off duty patrollers were out west and called in the first two avalanches. the appropriate level of response was initiated. i was heading out west to assess the snowpack

due to the changing conditions at the same time the avalanches had been called in. i met up with craig martella and Phil couch (day off Patrollers) as dispatch was making a net message over the radio about the event. i met up with the guys on skiers right of an area called ‘Solitude’ which is to the west of turoa and outside the ski area boundary.

we found the debris had run down from the upper mountain start zone. when i arrived, craig and Phil where doing a beacon search. the debris track had run into a tight drainage on the west flank of Solitude and was more than 1m deep in places and about 40m wide at our elevation 2350m. a couple of minutes after talking to Phil and assessing the situation, a lone backcountry skier turned up stating he had witnessed the slide. he said that he had observed ‘four snowboarders going through the area and four came out.’ at this stage Phil and craig were picking up no signals with their transceiver searches. this combined with the unknown factor of what was left in the start zones we decided to regroup at the ski area’s ‘Giant’ dispatch.

at the ridge line i interviewed the witness in more depth as more reports were coming in of an avalanche above the ski area and one running into ‘Slider’. a stream of 30 people at any one time are often hiking to the summit and this particular day was no different. >>

above: the Solitude event


the chance of a multiple casualty event was becoming increasing likely. we decided to close the upper part of the ski area and send a team to the summit to inform the climbers of the activity and advise them to descend.

this is when my phone rang with ryan making his daily contact call (the forecaster from whakapapa ski area). i briefed him with what was going on and ask him to put his crew on stand by, we also talked about transport to turoa and decided a helicopter was by far the safest and quickest. this would subsequently prove to be a good decision as the obvious route to turoa from whakapapa would later be found to have avalanched.

we all re-grouped at the Giant dispatch to form a search plan, the local police and the whakapapa crew arrived with their search dog and Keith mckenzie, an experienced local pilot. Both our search dogs were on the mountain at the Giant dispatch, which is very often the case when the Baa (Backcountry avalanche advisory) is on considerable. visibility was limited on ryan’s flight over but not long after their arrival we had a clearing and it was decided that a fly-by was needed to further investigate the avalanches we were dealing with. Brendon Nesbitt (a turoa Patroller) went on this assessment flight. on his return he confirmed that Paretetaitonga had actually ripped out and observed significant cracking on a number of other slopes. Ski tracks were noted in close proximity to a couple of the larger releases. after a quick discussion on team dynamics it was decided that two teams would further investigate two of these slides.

the high usage areas were going to be our focus. at this stage we still had no reports of anyone missing or caught in these avalanches, but any degree of uncertainty is reason enough for a comprehensive search. a combined rescue team of 20 patrollers with recco rescue equipment and three avalanche dogs responded and after searching for 40 minutes with no clues or strikes we started to lose visibility and daylight. confirmation from the ski area that it had been closed for some time and no one reported missing, we decided to call these areas clear and made our way back to base area for a debrief .

in conclusion this was a unique event with a high number of variables having to line up. By august 6 we had confirmed that a total of five decent sized avalanches (up to size three) had occurred.

what can we take out of this? Being more active in our passive control plan with closer monitoring during these conditions is a must. we are very lucky to have two strong certified avalanche search dogs and it was fortunate that the two dog handlers were on the mountain with their dogs. continue to promote more avalanche awareness and backcountry courses. we have identified the need for, and introduced a more structured avalanche rescue plan with varying levels of response depending on the size and nature of the event. ▲

above: ‘Gliding Gladys’ the main hiking route to the summit


industry has asked the Snow and avalanche committee of the NZmSc for a recommendation on the use of avalanche balloon bags as a safety device. the statement below was agreed upon by the committee at the recent meeting in early october 2012.

avaLaNChE BaLLOON BaGS // SaC updaTE

the use of avalanche balloon packs may increase a person’s chances of surviving if caught in an avalanche. however they do not guarantee survival and should not replace the carrying of transceivers, probes and shovels or good risk management decision making. the majority of the statistics being quoted about the use of balloon packs are used out of context and over rate the balloon packs effectiveness. there is still a significant chance of dying in an avalanche when wearing one. Greater risk taking by some users is likely to occur as their adoption increases. companies (and individuals) adopting the use of balloon packs should be wary of this and ensure measures are put in place to avoid increased avalanche incidents. Balloon packs do not offer very much if any increased protection to people caught in runout zones or in places with major terrain trap issues.

the wearing of avalanche balloon packs is a useful addition to the range of avalanche accident mitigation equipment. organisations thinking of adopting the use of balloon packs should undertake risk assessments of all aspects of their use and how their personnel interact with avalanche paths prior to adopting them. Not getting caught is the best option.

the use of balloon packs is most applicable to higher risk activities such as, ski patrollers doing avalanche control work who need to ski through unreleased start zones as part of control routes, heliski guides carrying out slope assessments prior to taking clients into the field and for alpine rescuers who need to travel through start zones or high in an avalanche path track. ▲


COmpariNG ThE SEaSONS - NEw zEaLaNd aNd COLOradO iN rEviEw // drEw GiBSON

drew is a ski patroller from copper mountain, colorado, and this winter made his New Zealand debut winter at temple Basin. in this article he shares his observations and compares his past experiences.

this first week of June brought up to 2m of snow to the arthur’s Pass area. videos of the train barreling through snowdrifts scattered the internet, webcams, and posts on facebook showed deep drifting and little ground hazard. i was watching this unfold on the other side of the world in sunny colorado, uSa. i remember being excited to get down to temple Basin and start work, but it would have to wait, we wouldn’t open for at least another 20 days.

Something i will always remember will be the initial drive up to arthur’s Pass from methven. the terrain relief was massive, but what was more impressive was how rugged it was. dense jungle, seemingly impassable, dominated the roadside. i couldn’t imagine passing through this terrain without significant effort and a whole lot of frustration.

i should give you a little background before i go any further. i’m from colorado. our mountains are high (more than 500 peaks 4000m and higher) and cold (well below 0°c most of the winter). this means harsh, windy winters, with not much snow. we are the epitome of a continental snow climate. we have a shallow, facet dominated snowpack. mid-winter conditions in the backcountry can be favourable on steeper lines, but it requires strong snowpack evaluation skills and the willingness to back down if conditions look less than adequate.

road access is good, with many high passes depositing you at 3000m and higher, so getting into the hills can be convenient depending on where you are going. But the most notable thing about colorado is the backcountry user base. there are literally thousands of backcountry users

above: Kiwi rail’s diesel powered avalanche generator. click here to view the video on youtube

ranging from skiers, climbers to snowmobilers. Parking lots [car parks] on busy passes are choked with cars, trailheads are full long before sunrise and multiple parties skiing from the same 4200m summit on a weekend day. all of this happens in possibly the worst mountain snowpack in the world. accidents happen every year and sometimes the endings are not happy ones.

CLuBBiES VS. ThE CoLorADo Ski ArEA

there is no such thing as a club field in the uS, much less colorado. i knew what the clubbies were about and i understood the workload and the community. copper mountain (my home resort) employs nearly 60 paid, fulltime patrollers, a small army. having 5000 guests on the mountain is a pretty standard day, so i welcomed the idea of small skier numbers and an even smaller staff.

working with the same two patrollers everyday keeps it consistent and simple. it also means that if anything goes wrong the rest of the operation can come to a grinding halt. one small knee injury can turn into an ‘all hands on deck’ problem very quickly. >>

http://youtu.be/6acPX_00M9Q


add in some unfavourable weather, and pretty soon you are carrying a patient out of the hills because the helicopter can’t make it in. it is quite the comparison to colorado where i can ski a patient down to a clinic in a few minutes and have an ambulance meet us there.

the largest difference between my uS home and NZ is the ability to throw money and/or man power at any problem until it is solved. the small, self-supported club field requires employees to be resourceful, self-starting and be able to ‘make do’. Sometimes the solution to a problem is not necessarily the right one, but the only solution feasible given the resources. i became aware of this immediately and decided to not let it get to me.

the unfavourable colorado climate and snowpack creates operational issues in regards to terrain management and requires alternative control methods to reduce hazards. to prepare terrain and avoid sending all the snow to the valley floor, we have an extensive boot packing programme that sends snow safety staff (and anyone else we can sucker into coming with us) walking down nearly every starting zone on the mountain at least once. By breaking down the existing layers, the snowpack is more likely to bond to itself and new snow. of course all bets are off if it does not snow for a long period of time, then the whole pack reverts to unconsolidated facets. the boot packing program has been successful at many areas in colorado and it is deemed necessary to open terrain as soon as possible. it also helps ease some of the uncertainty surrounding open terrain.

as you can guess we do not have the luxury of boot packing in the backcountry and even with the thousands of backcountry users, skier compaction is not considered viable when evaluating terrain. though the hazard may be reduced on some slopes, predicting the spatial variability with accuracy becomes a daunting and dangerous endeavor. the maritime snowpack appears to regulate itself far better, with danger often reducing within 24 hours of a weather event.

WEAThEr AND SNoWPACk

as mentioned before, cold temperature, frequent high winds and low snow totals drastically affect the snowpack. a storm bringing 10cm, moderate winds and below 0°c temperatures will produce exciting, reactive avalanche conditions, and pockets of excellent skiing.

like temple Basin and places close to the divide in arthur’s Pass National Park, my home turf in colorado is favoured by a strong Nw flow. this storm track snakes its way though the scattered rockies, releasing little moisture until it hits our zone roughly 40km along the west side of the continental divide. due to our proximity to the divide, storms on an easterly flow rarely reach us and if they do, snow totals are not worth mentioning.

due to colorado’s geography, Southerly storms pass through often, but as they are from the South they tend to be much warmer and have already released the bulk of their moisture. these systems are commonly accompanied by a warmer, light to moderate wind. Storms are rarely without wind, so a common hazard is new wind slabs. due to the

infrequency of storms, lower totals and most of all, higher temperature gradients, faceting layers are the primary concern. Between the always developing depth hoar, and multiple buried faceting layers, snow pits often have the ‘hard over soft’ or ‘upside down cake’ look. Sometimes it is a wonder how the snowpack is sticking to the mountain at all.

By mid-march things start turning around. the days are longer, the sun higher in the sky with warmer temperatures. you get used to wearing sunnies and light gloves, and then it happens, the spring storm cycles. warmer, intense snow falls can pummel colorado through to late april, sometimes until June. it is not uncommon for us to do lengthy control routes on the last day of operation and have shin-deep skiing during the mountain-wide cleanup day. these storm cycles hit at the perfect time for us because we are recently unemployed and have nothing to do but get into the hills and go skiing. colorado is a spring skiing paradise.

TErrAiN rELiEF AND CoMMiTMENT iN ThE roCkiES

where NZ has steep, dramatic high alpine and alpine faces, colorado’s terrain lends itself on the mellower side, right around 35-45 degrees. there are many pitches that are steeper, but the majority of the backcountry skiing/riding is done within this range. also, with the continental snowpack being much dryer than a maritime one, storm snow has a much more difficult time sticking to the steeper pitches. typically these steeper pitches (>50 degrees) come on closer to the Spring months, as the melt freeze cycle keeps things glued in place and the storms produce wetter snow.

though solid rock exists, the majority seems to be carefully stacked piles of rubble, ready to fall at any moment. this makes technical routes spicy and adds in an objective hazard that claims lives every season of every year.

though the mountains, elevation, climate and location vary greatly between NZ and colorado i think the biggest difference is the infrastructure. commercial ski resorts with 30-plus lifts, road access to high passes and trailheads change the way people think about skiing. Just like how backcountry skiing in NZ will make you rethink your ideas of effort and waterproof clothing.

all in all neither is a place that should be missed, both locations offer unique opportunities and experiences. coming to NZ for a season has helped me look at the big picture and given me a taste of ‘sole responsibility’, which is a scary thing to think about.

we had a less than average year and i can only imagine what it’s like when it’s good. hopefully next year i won’t have to, because a few months in NZ is far too little to get a handle on the ski/mountain culture. as i write this there is already a dusting of snow on the tops of the high peaks along the continental divide. the alpine ice has started forming and the ice tools have come out. winter is on its way and looking forward to next Spring i see myself packing up again and getting on a plane to head south, because there is still far too much to see. ▲


prOpOSEd ‘Kiwi BLOKE’ EdiTiON OF Nz daNGEr SCaLE

LEarNiNG aT ThE ‘ChapEL’

a new ‘Kiwi bloke’ edition of the NZ danger scale has been proposed by someone living in the twizel district with the initials Ba. the man from ‘uNcle’ has offered it to us for peer review before he takes it to iSSw – comments/amendments welcome.

when sitting at the ‘chapel’, workers on milford road’s avalanche programme never let a chance go by without seizing opportunities for further learning. those who visit this workstation often multi task as they brush up on their transceiver searching theory.

NEXT ISSUE OF CRYSTAL BALL DUE: 14 JunE 2013Submissions deadline due 30 april 2013

JUST FORFUN!

JUST FORFUN!


New Zealand’s outdoors is a great place to be and there are so many different ways to enjoy it. But before you set off on your adventure, take the time to plan and prepare for a safe trip.Follow the 5 simple rules of Outdoor Safety Code and make sure you tell someone your plans. Tell someone you trust where you are going and leave a date and time for when to raise the alarm if you haven’t returned.

Complete your outdoors intentions by downloading a form or entering your details online at www.adventuresmart.org.nz


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Extra food

Survival Kit

Emergency Shelter

Personal Locator Beacon

Firearms (w

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Mountain R

adio Call sign:

Satellite phone number:

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Terms &

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Type of vehicle etc. Please also include name of bus/rental car com

pany, if applicable:

e.g. name/address/telephone of accom

modation:

Registration no:

Make and m

odel:Colour:

Parked at:

If you are leaving a vehicle in the area for your return, please provide details below:

The Outdoors Intentions form

is provided free of charge but without w

arrant or guarantee. ‘OU

TDO

OR

S USER

’ refers to the person using the form to com

plete their Outdoors

Intentions. ‘TRU

STED CO

NTA

CT’ refers to the person that the ‘OU

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’ gives their Outdoors Intentions form

to, whether it be via electronic or hard copy m

eans. The process relies on the O

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OO

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SER providing correct and com

prehensive information. N

o responsibility is accepted for users providing incorrect information, including

incorrect email addresses. The process relies on the TR

USTED

CON

TACT receiving the inform

ation from the O

UTD

OO

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SER and follow

ing the designated process as set out on the form

. It is recomm

ended that the OU

TDO

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S USER

checks that their TRU

STED CO

NTA

CT has received the Outdoors Intentions (by w

hatever means chosen) prior

to leaving on a trip. It is the responsibility of the OU

TDO

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to ensure that the TRU

STED CO

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CT they select is willing and able to respond and follow

the process contained w

ithin the information they receive. N

o responsibility is accepted for the TRU

STED CO

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CT not receiving the information or not follow

ing the correct process. The tim

eliness and accuracy of a search and rescue response depends somew

hat on the quality, quantity and accuracy of the information that is provided by the O

UTD

OO

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U

SER to the TR

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TACT and that the TR

USTED

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s the process correctly. No guarantee is given regarding search and rescue response. Internet and

telecomm

unications providers do not guarantee uptime of their system

s or delivery of electronic messages. Postal services do not guarantee tim

eframes of delivery of physical

letters, parcels or packages. By using the O

utdoors Intentions form you accept that you have read, understood and agree to the term

s and conditions above.

AD

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verseas visitors please include your passport number and your nationality.)

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Address/Passport N

o./Nationality:

Address/Passport N

o./Nationality:

Phone:

Phone:

Phone:

Medical Conditions &

Medication:


Medication:


Medication:

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* If you need to add more group m

embers, please dow

nload the additional group mem

bers form.

Rem

ember to tell your Trusted Contact as soon as you have returned safely.

OU

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MN

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Safety is your responsibility so tell someone, it could save your life | w

ww

.adventuresmart.org.nz

OU

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OU

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(S) may select either of these options to

complete your O

utdoors Intentions details via a downloadable form

.

Option 2a. D

ownload the form

. Save to your system. Print form

. Com

plete details by hand and give to your TRU

STED CO

NTA

CT.

Option 2b. D

ownload the form

. Save to your system. Type

directly into the form. Save fi

le. Attach to an em

ail and send to your TR

USTED

CON

TACT.

None of the fi

elds on the form are com

pulsory, but the more

details you provide, the better the search and rescue agencies w

ill be able to respond should the alert be raised.

By using this form

you agree to the terms and conditions.

Whatever m

ethod you use, it is recomm

ended that you check that your TR

USTED

CON

TACT has received your O

utdoors Intentions prior to leaving on your trip.

You have been nominated as the TR

USTED

CON

TACT for the

OU

TDO

OR

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listed below, so you can raise the alarm

and contact the appropriate authorities if for any reason they do not return by the expected date and tim

e below.

TRU

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ber and your nationality.)

DD

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/ / :

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Start Date:

Family nam

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Nam

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Nam

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o./Nationality:

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o./Nationality:

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Num

ber & N

ationality:

Medical Conditions

& M

edication:


Medication:


Medication:

First name:

Cell Num

ber:

Hom

e Phone:

Intended track/route/huts and alternatives:

Note: A

lways enter your progress and changes to plan in hut logbooks, even if you don’t stay overnight.

Activity:

Time:

2 13

At the ‘expected date and tim

e’ below, im

mediately try

and contact the ‘OU

TDO

OR

S USER

’ directly, if you have not already heard from

them.

If unsuccessful try and contact other group mem

bers (if applicable).

If unsuccessful wait 1 hour and then repeat the process of

contacting the OU

TDO

OR

S USER

and if applicable other group m

embers. If unsuccessful and you are extrem

ely concerned or bad w

eather has set in, go straight to contacting the New

Z

ealand Police.

If you are still unsuccessful in contacting the OU

TDO

OR

S USER

or any m

embers of the party, telephone 111 (or if outside N

ew

Zealand call +64 4 381 2000) ask for the Police and tell them

you w

ish to report a missing person(s) w

ho is on a trip in the outdoors and has not returned by the expected date and tim

e. You w

ill need to provide the Police with the inform

ation below.

Rem

ember to tell your Trusted Contact as soon as you have

returned safely, to avoid unnecessary alarm and possible

involvement from

New

Zealand Police.

For tips, advice and links to help keep you safe throughout your land, snow

, water, boating and air activities in N

ew

Zealand, visit w

ww

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YOUR CUT OUT AND KEEP MASTER OUTDOORS INTENTIONS FORM - VISIT WWW.ADVENTURESMART.ORG.NZ TO FIND OUT MORE

crystal ball issue 21 vol spring 2012

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