“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 km 2. 40% of California. Mean annual flow = 600 m 3/sec. Sediment = 4. 2 X 106 tons/year
Human Impacts (years ago) • • 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 • Radioactivity • Destruction of Habitats • Chemical Pollution • Genetic Depletion • Climate Change
What We Cannot Control • 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 • 16 O, 17 O • • • and 18 O 8 protons 8, 9 and 10 neutrons = different masses Each behaves differently Warmer water = more 18 O More ice = more 18 O d 18 O
Earth to Sun Relationship: Orbit, Tilt, Equinoxes Interglacials Glacials
Climate/Sea Level Curve for the Past 500, 000 Years SF Bay = 7 X 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. • CO 2, CO, CH 4, 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 • • • Water Vapor Carbon dioxide Methane Chloroflourocarbons Ozone Nitrous oxide H 2 O CO 2 CH 4 (CFCs) O 3 NO
The Carbon Cycle • An atmosphere - terrestrial biosphere loop. • A terrestrial biosphere- geospherehydrosphere loop. • An atmosphere-geospherehydrosphere loop.
Temperature & CO 2 Variations Last 420, 000 years
Temperature & CO 2 Variations Last 18, 000 years
Temperature & CO 2 Variations Last 50 years
Greenhouse Changes
Natural & Human Climate Change
Courtesy of Ken Towe
Greenhouse Effects 1) 2) 3) 4) 5) 6) 7) 8) 9) Increasing CO 2 Increasing H 2 O: Flooding Increasing El Nino events Increasing temperature: 8 -12 OC Sea level rising: Up to 8+ m Increased hurricane & tornado occurrence/intensity Redistribution of crops & species Increasing diseases 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, 200 km 3 West Antarctica 3, 262, 000 km 3 Antarctic Peninsula 227, 100 km 3 Greenland 2, 620, 000 km 3 All other ice 180, 000 km 3 TOTALS: 64. 80 m 8. 06 m. 46 m 6. 55 m. 45 m 32, 328, 000 km 3 80. 32 m
When? 1000’s of years: Natural variations. 100’s of years: Human effects. 10’s of years: Sudden release of CH 4 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 • • • 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 • • • 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 • • • 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 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 2007 = 6, 650, 189, 946 2040 = 8, 900, 000 This in your lifetime!
In Your Kids’ Lifetime • • 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 1. 2. 3. 4. 5. ? ? ?
Thanks!! Jere H. Lipps jlipps@berkeley. edu
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