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Bay of Fundy:Tides and Sea Level Rise
SC 211, June 2, 2015 - Gary Oberts
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Causes of Sea Level Rise*
• Warming expands water (~50%)
• Glacier/ice sheet melt (~50%)
*Percentages currently under much discussion and revision as temps raise and ice melts
1947
2009
South Cascade Glacier, WA – 1960 and 2004 (NAS, 2008)
Wilkins Ice Shelf, Antarctica
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From Donaghue, 2011
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Peak SLR rate = 45mm/yr
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~0.1mm/yr
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From: CU Sea Level Research Group – Nov. 2014
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Today’s revised rate of SLR = +2.6 – 2.9 mm/yr.
(~0.1”/yr)
From Vermeer and Ramstorf,
2009
Sea Level Change
and Rate of
Change Since 1880
(red lines observed)
Rate Changes
Last 5K years = ~0.1mm/yr
20th Cent. = 1.7 mm/yr
1961-2003 = 1.8 mm/yr
Current (2015) = 2.6 – 2.9
mm/yr
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IPCC, 2007
2012 Updates
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Sen. James Inhofe’s Nov 2014 prediction of 1”
28”
71”
Complicating Factors: Building a
Realistic Scenario*
• Start with +1m SL increase
Add tides and exceptional (King) tides
Add wave run-up distance and height
(video) and possibility of extreme
(rogue, tsunami) waves
Add storm surges
*High water focus
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King Tides
Definition: extreme wintertime high tide events
that occur during spring tides as the result of
the combined gravitational forces of the sun
and moon.
“Broad” Beach, Malibu: Photos by Laurel Bartels, 2012
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LAT Broad Beach 2008
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Graphic from U. Wisc.
D
H
“Sea level rise acts as the baseline
reference point to which storm surge
height is added.” World Bank, 2009
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Wave Runup
http://www.youtube.com/watch?feature=player_detailpage&v=10PfxgbGBMg
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Coastal Flooding 2009-10
“Extreme” Waves
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“… coastal floods may reach locally rare heights more swiftly
in southern California than almost any other (23 studied) area,
when considering effects of sea level rise integrated with
storm surge patterns…”
From Tebaldi et al. (NOAA), 2012
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Accelerated erosion of slope toes
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Crystal Cove Erosion 2009-2010
~5’
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Photo and map from OC Register, March 2011
Recall highest tides with
1m SLR added in:
2011 = 11.3’
2012 = 9.6’
Seawalls now at 9’
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Pacific Institute, 2009Light blue = current 100-yr floodplain
Dark blue = modeled with +1.4m
(55”) rise by ~2100
Long
Beach
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Pacific Institute, 200927.
Pacific Institute, 2009
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Pacific Institute, 2009
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S.F. Bay
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San Diego Bay
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Questions? Slides will be posted on OLLI blog at https://olliuci.wordpress.com/
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Possible “Abrupt” Changes (IPCC, 2007)
• Ocean circulation and acidification
• Ice cover/glacier ablation
Sea level rise (coastal/island inundation)
• Hydrologic cycle (floods and droughts)
• Ecosystem changes
• Rapid release of methane from permafrost and ocean sediments
• Increased risk of species extinctions
Update May 2012 = 395
Latest predictions for range 550-1100
Sea levels 13-20’ (4-6m) higher than today with
temps 5-9ºF higher (~2100 prediction)
Last ice age ended ~10,000 years ago, sea levels about 390’ (120m) lower
Expected range for 2100
Long-term “modern” average ~280 ppm
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Tidal Surfing
Major Information Sources
• IPCC (Intergovernmental Panel on Climate Change)
• National Academies (Science and Engineering)
• U.S. Global Change Research Program (13 Fed. Agencies)
• CA Climate Change Center (core research at Scripps and UCB) and Climate Action Team (state agencies)
• National Science Foundation
• National Center for Atmospheric Research
• Climate peer-reviewed literature (lots!)
• World Bank
• U.S. Army Corps of Engineers
• UCSD-Scripps Coastal Data Information Program
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Tem
per
atu
re
Weather
“Weather” vs. “Climate”
Time
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NASA: Mean SLR = 3.18 +0.6 mm/yr
3.18mm/yr = ~1.3”/decade
over 1992-2012
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From U.S. Army Corps of Engineers, 2011
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550 - 1100??It’s not a catastrophic end of civilization but major adaptation to change and life as we know it; Problem is acceleration in rate of change not that earth has never seen these temps
Last ice age peaked ~20,000 years ago, sea levels about 390’ (120m) lower
Sea levels 13-20’ (4-6m) higher than today with
temps 5-9ºF higher (~2100 prediction)
Reference dates - Today 395 ppm
- IPCC 2007 380 ppm- IPCC 2002 360 ppm
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SL = -120m
SL = current
NOAA graphics14
ºF
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11
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CA Climate Change Research Center (2009)
< 20th Century SLR constant = 3.4 mm/yr/ °C
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Storm surges add intensity
Graphic buy John F. Henz
El Nino –
warmer
oceans, more
storm
intensityLa Nina –
cooler
oceans, less
storm intensity
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Graphic from Scripps Coastal Data Information Program, May 201233
Pop.>
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From Strauss et al., 2012
~Maryland ~1.2% of U.S.
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+1.5m
Olympia, WA - SLR Current “Worst-case” Scenario
(~0.8m)
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World Bank assessment of top
25 cities over 100,000
population and countries
impacted by rising sea levels
(2012)
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Alliance of Small Island States:
42 countries, 5% global
population
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Banda Aceh, Indonesia – 2004 Sumatra
(island) tsunami
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Mekong Delta, Vietnam
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Mekong River, Cambodia (tidal influenced)
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Malé, capital of
MaldivesShanghai
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Tuvalu – pop. 11,000 Tarawa, Kiribati –
pop.~30,000
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Other Effects of SLR
• Biophysical effects of SLR on coastal regions include:
- Inundation, flood and storm damage
- Wetland loss
- Erosion
- Saltwater intrusion
- Coral bleaching from higher sea water temperatures
- Ocean productivity changes and species migration.
• Socio-economic impacts
- Increased loss of property and coastal habitats
- Increased flood risk and potential loss of life
- Damage to coastal protection works and other
infrastructure
- Loss of renewable and subsistence resources
- Loss of tourism, recreation, and transportation
functions.57
Adaptation
• Disaster preparedness
• Evacuation
• Prediction
• Development planning, phased evacuation and
building codes
• Engineering upgrades
• Define impact zones (floodplains, wave runup,
wetlands)
• Assess infrastructure (floodwalls, erosion
prevention, drainage)
• Install detection systems(surges, waves)
• Focus international aid (ex. World Bank)
• Modernize insurance rates
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Why So Much Concern Now?
• Identified as most serious possible “abrupt” change by
IPCC in 2007 and more data showing that’s true
• Rate of rise has accelerated from ~1.7 mm/yr (0.07”)
during 20th century to 3.2 mm/yr (0.13”) over the past 20
years and up to 3.2-3.6 today
• This rate accelerating and expected to continue with
warming
• Related to SLR are:
– Storm surges
– Extreme high (“king”) tides and waves
– Coastal development
• CA study (SFSU, 2011) shows $100B property at risk for
1m SLR and $14B annually needed to protect property5
Impacts of Sea Level Rise: Not
Just a Third World Problem
• Biggest problem flooding especially if high tide occurs with storm surge, high waves and El Niño
• Major coastal erosion
• Salination of coastal groundwater, estuaries, wetlands
• Infrastructure impacts for CA ($100B at max. 55” rise)
– Transportation (highway, rail, shipping, air)
– Urbanized areas
– Oil, natural gas, electric facilities
– Water and wastewater treatment
– 104 Harbors/ports
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Oceans (sea level)
• CA coastal sea level increased 7-8” in last 100 years
• Predictions for CA are additional 24-55” rise by 2100*
• 100-year flood event will become a 10-year event
*From CA Climate Change Research Center 2009: IPCC 2007 predicted 7 – 23”
55”
24”
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Refs. NASA and French Space Agency, 2012
From Tebaldi et al. (NOAA), 2012 (Note: CA Climate Change Center predicts 0.3-0.45m SLR by 2050)
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From Strauss et al., 2012
Mean ~1.5m
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S.M. 2012*
High = +6.93’
Low = -1.58’
Add 3.3’ (1m)
New High =
10.23’
San Fran. =
10.1’
Balboa = 9.6’
(11.3’ actual
in 2011)
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*predicted
Average seasonal cycle of mean sea level
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Extreme wave height statistics for a 20-year return time (From: aviso.oceanobs.com)
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“Atmospheric Rivers”
From American Geophysical Union, 2011 and Scripps (Jan. 1988 photo)
Oct. 2009
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