Transcript San Francisco Bay: Interfacing ocean and rivers through

“Civilization exists by
geological consent . . .
subject to change without notice!”
Will Durant, 1926
San Francisco Bay
Through Time
Jere H. Lipps, UCMP Berkeley
San Francisco Bay
Largest estuary
west Americas.
300+ sq mi
Ave. depth=18 ft
Drains much of
California.
7 million people
live in area.
Large industrial
base.
San Francisco Bay & Delta
A very shallow, ephemeral estuary
Drainage to SF Bay
& Delta
~152,000 km2.
40% of California.
Mean annual flow = 600
m3/sec.
Sediment = 4.2 X 106
tons/year
Human Impacts (years ago)
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13,000: Arrival by sea and/or land
8,000: Began harvesting the new bay
2-3000: Built shell mounds
250: Europeans arrived; Native Americans
declined
• 160: California won from Mexico, Gold Rush
• 135: Bay filling began
• 100: Industrialization and development began
in earnest
> 100: Industrial global warming
Subject to:
Sea level changes.
Earthquakes.
Devastating fires.
Population
increase.
Pollution.
Invasions.
History Matters!
Conservation, Ecology
and Evolutionary
Biology as Historical
Sciences
What We Can
Control
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Radioactivity
Destruction of Habitats
Chemical Pollution
Genetic Depletion
Climate Change
What We Cannot Control
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Plate Tectonics
Sedimentation*
Global Climate Change*
Glacial Melting
Sea Level Changes
Natural Changes in Geology &
Biology*
What’s the Problem?
Nature
Us
California: Always Changing
From Hall 2005
Climate:
Always Changing
High Latitude Temperature
Changes Inferred from
Deep Sea Isotopic Records
Zachos et al. 2001
Temp C:
0
4
8
12
How Do We Know?
Oxygen isotopes of ice or microfossils
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16O, 17O
and 18O
8 protons
8, 9 and 10 neutrons = different masses
Each behaves differently
Warmer water = more 18O
More ice = more 18O
d18O
Earth to Sun Relationship:
Orbit, Tilt, Equinoxes
Interglacials
Glacials
Climate/Sea Level Curve for
the Past 500,000 Years
SF Bay = 7X
p.s.l.
No SF Bay
10
100
200
300
400
years X 1000
500
Mostly, SF Bay was a river valley
Glacial Earth
What is Global Warming?
• Certain gases in atmosphere trap heat,
like in a Greenhouse.
• CO2, CO, CH4, NO, & others.
• Contributed by volcanoes, some other
sources, and now human activities.
• Nature can’t remove it fast enough.
• Atmosphere & ocean linked. Both
warm, not necessarily smoothly.
• Venus & Mars are Greenhouse planets.
Greenhouse Gases
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Water Vapor
Carbon dioxide
Methane
Chloroflourocarbons
Ozone
Nitrous oxide
H2O
CO2
CH4
(CFCs)
O3
NO
The Carbon Cycle
• An atmosphere - terrestrial
biosphere loop.
• A terrestrial biosphere- geospherehydrosphere loop.
• An atmosphere-geospherehydrosphere loop.
Temperature & CO2 Variations
Last 420,000 years
Temperature & CO2 Variations
Last 18,000 years
Temperature & CO2 Variations
Last 50 years
Greenhouse Changes
Natural & Human Climate Change
Courtesy of
Ken Towe
Greenhouse Effects
1)
2)
3)
4)
5)
6)
Increasing CO2
Increasing H2O: Flooding
Increasing El Nino events
Increasing temperature: 8-12OC
Sea level rising: Up to 8+ m
Increased hurricane & tornado
occurrence/intensity
7) Redistribution of crops & species
8) Increasing diseases
9) Major changes in oceans & biotas
Patagonia: Always Changing
Glacial Retreat
80 m since 2000;
more to come in next 30 years
San Francisco:
Sea Level Rise
Potential Sea Level Rise
East Antarctica 26,039,200km3
West Antarctica 3,262,000km3
Antarctic
Peninsula
227,100km3
Greenland
2,620,000km3
All other ice
180,000km3
TOTALS:
64.80m
8.06m
.46m
6.55m
.45m
32,328,000km3 80.32m
When?
1000’s of years: Natural variations.
100’s of years: Human effects.
10’s of years: Sudden release of
CH4 clathrates,
Catastrophic collapse
of ice sheets.
and inferred for
the future. ~8 m
sea level rise.
Road Damage: 1.5 m Rise
Pacific Institute
Fire Hazard Will Increase
East Bay Fires
History
• Fire is a natural
part of the East
Bay environment
• Major fires have
occurred every
10 to 15 years
in the East Bay
hills
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1923: 130 acres , 584 homes
1931: 1,800 acres, 5 homes
1933: 1,000 acres, 5 homes
1937: 700 acres
1946: 1,000 acres
1960: 1,200 acres, 2 homes
1970: 204 acres , 37 homes
1980: 2 acres, 5 homes
1990: 200 acres
1991: 1,700 acres, 3,400
homes, 25 died
• 1995: 3 homes
• 2002: 5 acres
The 1923 Berkeley Fire
Destroyed 584 Homes in
2 HOURS
Oakland
Hills
Fire
from
space
NASA
Losses 1991 Oakland Hills Fire
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25 Dead
150 Injured
3,471 Homes Lost
1,520 Acres Burned
Largest Fire Loss in the history of the
nation up to that time - $2.2 billion
• Economic Loss: 15-20% business
failure in nearby retail, citywide
unknown
1910
2003
Tilden Park
Source: Jean Quan
Living in the Hills
Each arrow = house
Source: Jean Quan
San
Andreas
Fault
System
>60% chance
of a 6.7 quake
in next 30
years in Bay
Area
Ten Greatest Quakes
A Few California Quakes
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San Francisco
Calaveras fault
Imperial Valley
Kern County
San Fernando
Coalinga
Loma Prieta
Northridge
Parkfield
1906
1911
1940
1952
1971
1983
1989
1994
2004
8.25
6.5
7.1
7.7
6.5
6.5
7.1
6.7
7.0
Oak Knoll
Hospital
1971
Bay Area Faults
Probability of
Earthquakes
> 6.7
2003-2032
= 62%
USGS
http://quake.usgs.gov/
Rock Type Makes a Difference
Liquification: East Bay
San Andra
San
Andreas
Fault
7.2
Hayward
Fault
6.9
University of California,
Berkeley
UCB
Memorial Stadium
You Need an
Earthquake
Bucket!!
The Real Problem
A World Full of Humans
1960 = 3,000,000,000
2007 = 6,650,189,946
2040 = 8,900,000,000
This in your lifetime!
In Your Kids’ Lifetime
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World population will increase 3 billion
US population will increase 50 million
Petroleum will be used up
Sea level will rise 1-8+m
Climate will warm several degrees
Oceans will acidify
Fishing will decrease
Biodiversity & abundance will decrease
enormously
ONLY YOU CAN HELP YOUR CHILDREN,
GRANDCHILDREN & YOURSELF
What
can
you do
for your
Bay
Area?
NASA
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Thanks!!
Jere H. Lipps
[email protected]