January 30, 2003

Exploring Mars
Recent Discoveries and Upcoming Missions

• Thirty years of Mars exploration have revealed a spectacularly diverse planet
• Dry river valleys and layered sediments suggest a warm, wet past
• Huge f oods may have created transient oceans
• Towering volcanoes, deep canyons, and global fracture systems dwarf their counterparts on Earth
• Two US rovers and a European lander, to be launched this May and reach Mars in January 2004, are expected to shed new light on how the planet evolved

February 27, 2003

Is Your Neighborhood Going Downhill?
How Landslides Threaten Bay Area Lives and Property

• Landslides-the underrated hazard-cost the Nation billions of dollars in property damage annually
• How do our local geologic conditions make the Bay Area an ideal habitat for landslides?
• El Nino storms or other heavy rains can activate dormant slides
• Recent Bay Area landslides, such as Devil's Slide (1995), Polhemus Road (1997), La Honda (1998), Mission Peak (1998), and Daly City (1999), remind us of the danger
• What makes certain kinds of landslides life-threatening?

March 27, 2003

The November 2002 Denali Fault Earthquake
Was This Alaska Shock a Preview of California's Next "Big One"?

• This powerful magnitude 7.9 quake ruptured the fault for 184 miles, creating offset as great as 29 feet and causing thousands of landslides
• The quake's shaking was felt in Anchorage and produced effects as far away as Louisiana
• Although the ground shifted 14 feet beneath the Trans-Alaska Oil Pipeline, the pipe did not break, a tribute to careful geologic studies and creative engineering
• The San Andreas Fault is similar to the Denali Fault and produces comparable quakes, but unlike the Denali, runs through densely populated urban areas
• Will intensified monitoring of the Denali Fault enable us to forecast where and when the next major quake will strike on that system?

April 24, 2003

Gaia's Breath
Methane and the Future of Natural Gas

• The Earth--or "Gaia," the Earth Goddess of Ancient Greece-- exhales more than 1 million tons of methane each day
• Mud volcanoes around the world emit about 5 million tons of methane each year as part of Gaia's breath
• Energy sources used by society have evolved from wood to coal to oil and natural gas.soon possibly to hydrogen extracted from natural gas?
• Gas hydrate--"ice that burns"--found under the sea and in permafrost regions, is a potential future source of energy

May 22, 2003

The National Map -- Coming to Your Neighborhood!
Integrating and Sharing Geographic Information in the Public Domain

• Begun by the USGS in 2001, The National Map is a 10-year vision for a seamless, constantly updated, national geospatial database
• This vast public database will be continually updated through local partnerships, selectively printable, and available on the Internet and at neighborhood kiosks
• Implementation projects --such as the Lake Tahoe and Sacramento areas--demonstrate the benefi ts of integrating high-resolution local datasets
• With the current focus on homeland security, datasets for 10 U.S. urban areas are scheduled for completion this year, at a resolution of 0.3 meter (1 foot)
• Because many printed maps are more than 20 years old, The National Map will be of great value for multiple uses, including planning, disaster response, and recreation

June 26, 2003

The Quakes, They Are A-comin'--
New Estimates of Earthquake Hazard and Risk Across the Bay Region

• A USGS-led Working Group has used new ideas about Bay Area faults and earthquakes to revise the probabilities for future quakes
• The slow movement of the Earth.s plates builds up stress that is relieved in violent earthquakes.where are we now in this relentless cycle?
• Earthquakes can.t yet be predicted, but scientists can estimate probabilities of their occurrence
• New scenario ShakeMaps provide a guide to expected shaking and damage from future quakes

July 31, 2003

Molten Paradise
Video Presentation and Discussion

See-

• The dramatic nonstop Pu'u O'o eruption, now entering its 21st year
• Rivers of glowing lava flow through underground tubes
• Scientists collect samples of molten rock hotter than 2000 F
• Lava ooze and drip down sea cliffs into the surf
• Scientists explain how volcanic eruptions built the Hawaiian Islands

August 28, 2003

Human Footprints on the Web of Life
Biodiversity and Increasing Population and Development in California

• Why does California lead the country in endangered species--why are so many reptiles and amphibians in decline?
• Learn about the California lizard that keeps Lyme disease in check and the butterflies that prevented development on San Bruno Mountain
• California faces growing economic costs from fire ants, Asian clams, and other aggressive invasive species
• The megamouth shark occurs off our coast, but was not discovered until 1976--what else do we still not know?
• How will California's spreading asphalt (already 5 million acres) affect future biodiversity? Thursday August

September 25, 2003

Beneath Crater Lake
An underwater volcanic landscape tells a complex tale

• Crater Lake, a jewel of the National Park system, partly fi lls a caldera basin formed during a giant volcanic eruption 7,700 years ago
• Deepest of all U.S. lakes, Crater Lake has no surface outlet.how does its fresh water leave the lake?
• Cooperative studies by USGS, National Park Service, and university scientists have probed the lake's secrets
• New high-precision echo sounding and GPS navigation techniques "strip away" the water to reveal volcanoes, lava deltas, and giant landslides

October 30, 2003

Creatures of the Night
A Witch's Brew of Bays and Beasts

• The Bay Area's nocturnal fauna includes 12 species of bats and much more--see what else is out and about in the dark
• Separate day, night, and maternity roosts give many bats multiple homes
• Some bats eat 600 mosquitoes in an hour, but not all feed on flying insects--what else is on their menu?
• Automated bat-monitoring stations reveal the movements and lifestyles of local bats
• Bat vocalizations can be lowered into the range of human hearing--would you like to hear what a bat sounds like?

November 20, 2003

CLEAN POWER FROM THE EARTH'S HEAT
The Present and Future of Geothermal Energy

• Since ancient times, people have sought out geothermal hot springs for bathing, cooking, and supposed healing effects
• In Iceland, nearly half the electrical power and all space heating are derived from geothermal sources
• For Iceland and other volcanic regions of current volcanism, large-scale generation of geothermal energy is a viable, environmentally friendly alternative to fossil fuels
• Did you know that Northern California has the world.s largest electricity-generating geothermal development?
• Geothermal heat pumps can provide cost-effective space heating and cooling, almost anywhere

December 11, 2003

WHAT'S HAPPENING TO ALASKA'S GLACIERS?
Their Dynamic Response to Changing Climate and Other Factors

• Although the oceans contain more than 95% of the Earth.s water, glaciers hold 75% of the fresh water
• If all the world's glaciers melted, sea level would rise more than 250 feet
• Of Alaska.s 2,000 or so large glaciers, more than 99% are now retreating or stagnating
• Photos taken decades apart at Glacier Bay reveal the dynamic evolution of the glacial landscape
• Why are Alaska's glaciers now contributing more water to raising sea level than Antarctica and other polar areas?