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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

3

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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