nature, 454, 2008 the third poleneespi.org/web-content/meetings/bishkek_2009/day3.7_fujita.pdf ·...

The Third PoleThe Third PoleNature, 454, 2008

The Third Pole The Third Pole

The largest ice mass other than AntarcticaThe largest ice mass other than Antarctica The largest ice mass other than Antarctica The largest ice mass other than Antarctica and Greenland…and Greenland… This is not true butThis is not true but This is not true, but,This is not true, but,

Their rapid changes are important!!Their rapid changes are important!!

www.cryoscience.netwww.cryoscience.net

Significance of Asian GlaciersSignificance of Asian GlaciersDyurgerov & Meier [1997, AAR]

Significance of Asian GlaciersSignificance of Asian Glaciers

Large contrib tion to mass loss of small glacierLarge contrib tion to mass loss of small glacier Large contribution to mass loss of small glacierLarge contribution to mass loss of small glacier Huge area & rapid shrinkageHuge area & rapid shrinkage

Region (1960s~90s)Region (1960s~90s)AreaArea×× 101033 kmkm

%%M.B.M.B.mm yrmm yr--11 %%

Arctic islandsArctic islands 244244 3535 --6767 2020AlaskaAlaska 7575 1111 --101101 99AsiaAsia 119119 1818 --339339 4848EuropeEurope 1818 33 153153 --33EuropeEurope 1818 33 153153 33US/CanadaUS/Canada 4949 77 --323323 1919Greenland & Antarctic small glaciersGreenland & Antarctic small glaciers 140140 2121 --4646 88S th HS th H 3535 55 00


South Hem.South Hem. 3535 55 -- 00GlobalGlobal 680680 100100 100100

Glacier Distribution in AsiaGlacier Distribution in AsiaDyurgerov & Meier [1997, AAR]

Glacier Distribution in AsiaGlacier Distribution in Asia

Himalayan glaciers account for 30%Himalayan glaciers account for 30% Himalayan glaciers account for 30%Himalayan glaciers account for 30%

13

11

1114

729


Recent changes in benchmark Recent changes in benchmark glaciers in the Nepal Himalayaglaciers in the Nepal Himalayaglaciers in the Nepal Himalayaglaciers in the Nepal Himalaya

Koji FujitaKoji FujitaNagoya UniversityNagoya UniversityNagoya UniversityNagoya University

www.cryoscience.netwww.cryoscience.net T. Nuimura, S. Okamoto, Y. Hoshina, H. Nagai

Himalayan Benchmark GlaciersHimalayan Benchmark GlaciersHimalayan Benchmark GlaciersHimalayan Benchmark Glaciers

Three glaciers have been monitored sinceThree glaciers have been monitored since Three glaciers have been monitored since Three glaciers have been monitored since the 1970sthe 1970s


How Do We Monitor Them?How Do We Monitor Them?How Do We Monitor Them?How Do We Monitor Them?

Continuous measurement by stakeContinuous measurement by stake Continuous measurement by stake Continuous measurement by stake method is unpractical for us!!method is unpractical for us!!

Geodetic by theodolite or differential GPSGeodetic by theodolite or differential GPS Geodetic by theodolite or differential GPSGeodetic by theodolite or differential GPS

A guy having prism↓

GPS antenna↓

↓

www.cryoscience.netwww.cryoscience.net Ganju La Glacier, BhutanOct 2004

Fedchenko Glacier, PamirTwo weeks ago

Glacier AX010Glacier AX0102008Fujita et al. [2001]

Glacier AX010Glacier AX010

Since 1978Since 1978 Since 1978Since 1978 Mass balance for 1995Mass balance for 1995--19991999

199819891978

Appeared in..

199819891978

2008


Yala GlacierYala GlacierFujita et al. [1998]

Yala GlacierYala Glacier

Since 1982Since 1982 Since 1982Since 1982 Drastic retreat Drastic retreat

after 2000?after 2000?after 2000?after 2000?

1996

www.cryoscience.netwww.cryoscience.net 2008

Rikha Samba GlacierRikha Samba GlacierRikha Samba GlacierRikha Samba Glacier

Since 1974Since 1974 Since 1974Since 1974 We plan to visit We plan to visit

this Oct to Novthis Oct to Novthis Oct. to Nov.this Oct. to Nov.

1974


1994 Fujita et al. [1997]

Survey ResultsSurvey ResultsSurvey ResultsSurvey Results

Dens measured pointsDens measured points Dens measured pointsDens measured points Creating digital elevation models (DEMs)Creating digital elevation models (DEMs) New baseNew base map for future surveymap for future survey New baseNew base--map for future surveymap for future survey

Superimpose previous surveysSuperimpose previous surveysC fC f Change in surface height on glacierChange in surface height on glacier

Ice disappeared areaIce disappeared area


Changes in Himalayan GlaciersChanges in Himalayan GlaciersFujita et al. [1997; 1998; 2001; in prep.]

Changes in Himalayan GlaciersChanges in Himalayan Glaciers

Rapid shrinkage compared with glaciersRapid shrinkage compared with glaciers Rapid shrinkage compared with glaciers Rapid shrinkage compared with glaciers worldwide worldwide ~500 mm yr~500 mm yr ––11 for the 1990sfor the 1990s ~500 mm yr~500 mm yr 11 for the 1990sfor the 1990s

www.cryoscience.netwww.cryoscience.net 2008/09

How Apply Survey Results?How Apply Survey Results?How Apply Survey Results?How Apply Survey Results?

These observational data are so localizedThese observational data are so localized These observational data are so localizedThese observational data are so localized Depending on precipitation and other Depending on precipitation and other

meteorological variablesmeteorological variables One approach: mass balance modelingOne approach: mass balance modeling Need Need inin--situsitu meteorological data for meteorological data for gg

downscaling redownscaling re--analysis dataanalysis data Alternative: remote sensing digital Alternative: remote sensing digital

elevation models (DEMs)elevation models (DEMs) No validation in the HimalayasNo validation in the Himalayas


How Apply Survey Results?How Apply Survey Results?How Apply Survey Results?How Apply Survey Results?

These observational data are so localizedThese observational data are so localized These observational data are so localizedThese observational data are so localized Depending on precipitation and other Depending on precipitation and other

meteorological variablesmeteorological variables One approach: mass balance modelingOne approach: mass balance modeling Need Need inin--situsitu meteorological data for meteorological data for gg

downscaling redownscaling re--analysis dataanalysis data Alternative: remote sensing digital Alternative: remote sensing digital

elevation models (DEMs)elevation models (DEMs) With validation in the HimalayasWith validation in the Himalayas


Studies using RSStudies using RS--DEMsDEMsStudies using RSStudies using RS DEMsDEMs

Recent advanced RSRecent advanced RS--DEMs allow toDEMs allow to Recent advanced RSRecent advanced RS DEMs allow to DEMs allow to analyze glacier changesanalyze glacier changes No baseNo base map for Himalayan glaciersmap for Himalayan glaciers No baseNo base--map for Himalayan glaciersmap for Himalayan glaciers


Target Area & Data UsedTarget Area & Data UsedTarget Area & Data UsedTarget Area & Data Used

Khumbu region east NepalKhumbu region east Nepal Khumbu region, east NepalKhumbu region, east Nepal Digital Elevation Models (DEMs)Digital Elevation Models (DEMs)

ASTER L3A01 d tASTER L3A01 d t ASTER L3A01 productsASTER L3A01 productsEvery year since 2001 Every year since 2001 -- 20082008

SRTM3 2000SRTM3 2000 SRTM3, 2000SRTM3, 2000 Topographical mapTopographical map

1/50 000 f i l h t i 19921/50 000 f i l h t i 1992 1/50,000 from aerial photo in 19921/50,000 from aerial photo in 1992 Aerial photogrammetry DEMAerial photogrammetry DEM

Aerial photo in 1984Aerial photo in 1984 [G t l 2002][G t l 2002]


Aerial photo in 1984 Aerial photo in 1984 [Gruen et al. 2002][Gruen et al. 2002]

Nuimura et al. [in prep]

Digitizing Topographical MapDigitizing Topographical MapDigitizing Topographical MapDigitizing Topographical Map

Photo taken in 1992Photo taken in 1992 Photo taken in 1992Photo taken in 1992 Nepal & Finland projectNepal & Finland project


Aerial Photogrammetry DEMAerial Photogrammetry DEM[Gruen et al. 2002]

Aerial Photogrammetry DEMAerial Photogrammetry DEM

Original photo takenOriginal photo taken Original photo taken Original photo taken in 1984in 1984 For National GeographicFor National Geographic For National GeographicFor National Geographic


Differential GPS SurveyDifferential GPS SurveyDifferential GPS SurveyDifferential GPS Survey

OctOct -- Nov 2007Nov 2007 Oct. Oct. Nov. 2007Nov. 2007 Base station atBase station at

SyangbocheSyangbocheSyangbocheSyangboche 30 km 30 km ×× 30 km area30 km area Not for glacier,Not for glacier,

but for nonbut for non--glacierglacierterrainterrain


Validate DEMsValidate DEMsValidate DEMsValidate DEMs

Offsets and standard deviationsOffsets and standard deviations Offsets and standard deviationsOffsets and standard deviationsDate Offset

(m)SD (m)

Aero DEM 1984 48.3 11.8

Top DEM 1992 29.3 22.6

SRTM3 2000 29.8 10.0

Dec. 2001 -11.2 14.1

Nov. 2002 -18.3 15.2

Oct. 2003 -19.6 13.1

Nov. 2004 -16.2 13.3

ASTER DEM Nov. 2005 -10.8 11.0

Dec. 2005 -13.1 12.0

Feb. 2006 -16.9 11.6


Jan. 2008 -21.7 12.3

Feb. 2008 -15.4 14.1

Discarding Bad PixelsDiscarding Bad PixelsDiscarding Bad PixelsDiscarding Bad Pixels

Voids clouds and steep slopes areVoids clouds and steep slopes are Voids, clouds, and steep slopes are Voids, clouds, and steep slopes are excluded on GISexcluded on GIS

(SRTM3) (Topographical map) (ex ASTER 2008)


(SRTM3) (Topographical map)

Void in SRTM Good Case

(ex. ASTER 2008)

Cloud/snow Effect

Screening Large AnomalyScreening Large AnomalyScreening Large AnomalyScreening Large Anomaly

Iterative screeningIterative screening Iterative screeningIterative screening

H i ht h i tHeight changing rate

Anomaly value → Excluded →


Changes in Glacier Surface HeightChanges in Glacier Surface HeightChanges in Glacier Surface HeightChanges in Glacier Surface Height

250 mm yr250 mm yr --11 for 1984for 1984--20082008 250 mm yr250 mm yr for 1984for 1984 20082008


Validation: Khumbu GlacierValidation: Khumbu GlacierValidation: Khumbu GlacierValidation: Khumbu Glacier

Good agreement with surveysGood agreement with surveys Good agreement with surveysGood agreement with surveys 370 mm yr370 mm yr --11 for 1984for 1984--2008 2008


Effect of Imja Glacial LakeEffect of Imja Glacial LakeEffect of Imja Glacial LakeEffect of Imja Glacial Lake

Enhanced lowering at glacial lake contactEnhanced lowering at glacial lake contact Enhanced lowering at glacial lake contactEnhanced lowering at glacial lake contact


ConclusionsConclusionsConclusionsConclusions DebrisDebris--free glaciers show significant lowering in free glaciers show significant lowering in g g gg g g

the last few decadesthe last few decades High sensitivity of monsoonal glaciers High sensitivity of monsoonal glaciers [[FujitaFujita 20082008EPSL]EPSL]

MultiMulti--temporal remote sensing DEMs provide temporal remote sensing DEMs provide smaller lowering rates of glacier surface heightsmaller lowering rates of glacier surface heightsmaller lowering rates of glacier surface heightsmaller lowering rates of glacier surface height Increase at the upper accumulation areaIncrease at the upper accumulation area Small lowering rates of debrisSmall lowering rates of debris--covered areacovered area

Himalayan ices are still tolerant!?Himalayan ices are still tolerant!? Glacial lakes give positive feedback on rapid Glacial lakes give positive feedback on rapid

lowering of glacierslowering of glacierswww.cryoscience.netwww.cryoscience.net

lowering of glacierslowering of glaciers

For FutureFor FutureFor FutureFor Future

Keeping monitoring benchmark glaciersKeeping monitoring benchmark glaciers Keeping monitoring benchmark glaciersKeeping monitoring benchmark glaciers Intermittent geodetic monitoringIntermittent geodetic monitoring Obtaining precise baseObtaining precise base--map for futuremap for futureObtaining precise baseObtaining precise base map for futuremap for future ELA above glacier maximumELA above glacier maximum

New glaciers extending higher elevationNew glaciers extending higher elevation

Higher resolution RSHigher resolution RS--DEMs are welcomeDEMs are welcome ALOS PRISMALOS PRISM--DEM has high potentialDEM has high potential Need validationNeed validation


Thank you


Photo courtesy of T. Takeda

nature, 454, 2008 the third poleneespi.org/web-content/meetings/bishkek_2009/day3.7_fujita.pdf ·...

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