News and Information: News-January 2007

The 1906 M=7.9 earthquake on the San Andreas Fault marked the birth of modern earthquake science in the U. S. For the first time, an earthquake was interpreted as a recurring phenomena along an active fault.  The trace of the San Andreas fault was mapped throughout California and offset on the 300 km long surface rupture documented. Comprehensive study of seismic intensity showed the strongest shaking occurred in areas of "made land" (fill) and soft sediment, including China Basin and the present day Marina district, two San Francisco neighborhoods again heavily damaged in 1989. Damage to structures showed destruction was closely related to building design and construction -- a painful lesson oft repeated around the world. Based on repeated surveying data and geologic evidence of recurrence, Henry Reid proposed the elastic rebound hypothesis -- that earthquakes represent sudden release of elastic energy along a fault resulting from a cycle of slow strain accumulation produced by relative displacements of neighboring portions of the crust. This hypothesis, developed five decades before the plate tectonics revolution provides the basis for modern seismic hazard analysis. We now know that a repeat of the 1906 earthquake is only one of a wide number of future major damaging earthquakes likely to impact the Bay Area. Although we can not predict earthquakes, we can predict their likely effects and the most hazardous regions.

The Emporium

February - Paleogeography of the Ancestral Rockies, Chuck Kluth, rescheduled from December

April - Family Night

June - Spring field trip to San Luis Basin with Mike Machette

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Please make your checks payable to the Colorado Scientific Society

Colorado Scientific Society’s regular meetings are held the 3rd Thursday of the month at the American Mountaineering Center in Golden (unless otherwise advertised). Social time begins at 6:30 p.m. and talks start at 7:00 p.m. For more information, contact Chuck Kluth at 303-904-2939, kluth@earthlink.net

Denver Mining Club meets every Monday (except when noted) at Country Buffet near Bowles and Wadsworth (at 8100 W. Crestline Ave.) 11:30-1:00. Jan. 8, Margaret McDonald, Snake River Alliances, "Nuclear waste do's and don't's".  Jan. 22, Stuart Sanderson, CMA, Colorado mining and climate change"..Jan. 29, Sam McGeorge, "National Mining Hall of Fame and Museum update".   http://china-resources.net.