San Francisco Bay Through Time


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San Francisco Bay Through Time



San Francisco Bay



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)

  • 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





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



Climate: Always Changing



How Do We Know?

  • Oxygen isotopes of ice or microfossils

  • 16O, 17O and 18O

  • 8 protons

  • 8, 9 and 10 neutrons = different masses

  • Each behaves differently

  • Warmer water = more 18O

  • More ice = more 18O

  • 







Mostly, SF Bay was a river valley







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

  • Water Vapor H2O

  • Carbon dioxide CO2

  • Methane CH4

  • Chloroflourocarbons (CFCs)

  • Ozone O3

  • Nitrous oxide NO



The Carbon Cycle

  • An atmosphere - terrestrial biosphere loop.

  • A terrestrial biosphere- geosphere-hydrosphere loop.

  • An atmosphere-geosphere- hydrosphere 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





Greenhouse Effects

  • 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

  • Redistribution of crops & species

  • Increasing diseases

  • Major changes in oceans & biotas



Patagonia: Always Changing Glacial Retreat





Potential Sea Level Rise

  • East Antarctica 26,039,200km3 64.80m

  • West Antarctica 3,262,000km3 8.06m

  • Antarctic Peninsula 227,100km3 .46m

  • Greenland 2,620,000km3 6.55m

  • All other ice 180,000km3 .45m

  • TOTALS: 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.





Road Damage: 1.5 m Rise



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



The 1923 Berkeley Fire Destroyed 584 Homes in 2 HOURS





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





Living in the Hills Each arrow = house



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 1906 8.25

  • Calaveras fault 1911 6.5

  • Imperial Valley 1940 7.1

  • Kern County 1952 7.7

  • San Fernando 1971 6.5

  • Coalinga 1983 6.5

  • Loma Prieta 1989 7.1

  • Northridge 1994 6.7

  • Parkfield 2004 7.0







Bay Area Faults



Probability of Earthquakes > 6.7 2003-2032 = 62%



Rock Type Makes a Difference



Liquification: East Bay



San Andra





University of California, Berkeley



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

  • 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?



Thanks!!

  • Jere H. Lipps

  • jlipps@berkeley.edu





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