Mark Your Calendars
Help San Diego defend its national title as Birdiest City (2002) and Birdiest County (2004) by taking your binoculars into the field April 28 to 30.
For information E-mail Phil Pride, San Diego Audubon Society, at philpinsd@cox.net.
EARTH FAIR
Celebrate Earth Day in Balboa Park and check out the alternative fuel vehicle parade and eHome exhibit.
April 23; 10 a.m. to 5 p.m.
http://www.earthday web.org
GRUNION RUN
Join Scripps naturalists to marvel at female grunion coming ashore to spawn in moonlight.
Birch Aquarium; April 15, 9:45 p.m.
Nonmembers: $12 adults; $9 children; (858) 534-7336; aquarium.ucsd.edu/
When San Francisco shook
At 5:12 a.m., April 18, 1906, a foreshock was felt widely throughout San Francisco. The great earthquake broke loose 20 seconds later, with violent shocks for up to a minute. It was felt from Oregon to Los Angeles, and inland as far as central Nevada. When it was over, the ground had broken open for more than 270 miles along the San Andreas fault. People living on the east side had moved south, in some places as much as 21 feet.
From the disaster came an increased understanding of the processes that shake our Earth.
Analysis of the earthquake led geologist Henry Fielding Reid in 1910 to formulate the elastic rebound theory – the first scientific theory of how earthquakes occur. He posited that Earth's crust can gradually store elastic stress that is released suddenly during an earthquake, much as a stretched rubber band will snap when broken. Scientists today know that most earthquakes occur in this way.
To commemorate the 100th anniversary of the great San Francisco earthquake, the San Diego Natural History Museum presents a lecture series to address the past, present and future of earthquake science.
San Diego Natural History Museum; (619) 255-0203; www.sdnhm.org; Nonmembers: $8 single lecture; $24 series
All lectures at 7 p.m.
The Future of Earthquakes
Are you prepared for more?
Geologist Pat Abbott, SDSU, with Dean and Dran Reese; April 18
Lessons Learned, Lessons Forgotten
Mary Lou Zoback, U.S. Geological Survey
Understanding earthquake hazards and reducing risks. April 26
Giant Earthquakes: Why, Where, When and What We Can Do
Seth Stein, Northwestern University
Understanding the physics of the Indonesia super temblor. May 8
Vibrations From the Deep: Deciphering Earth's Surface
Ed Garnero, Arizona State University
New seismic imaging techniques reveal exotic internal structures deep within Earth.
May 17
EDITOR'S CHOICE
Since 2000, wildlife biologist Mike Puzzo has radio-collared 21 mountain lions in eastern San Diego County, mostly in the Anza-Borrego Desert. He has observed their kills and unearthed their caches of dead deer and bighorn sheep.
You can spend the day in the backcountry with Puzzo, investigating the scene of a mountain lion kill and peppering him with questions about the big cats. Expect some serious rock scrambling.
Anza-Borrego Institute
April 22, May 7 or May 13; 9 a.m. to 4 p.m.
$45 Nonmembers
(760) 767-0446; www.theabf.org
Send ideas for Extracurricular to leigh.fenly@uniontrib.com.
