2003 - 2004 Public Lecture Series
at Caltech

Please join our fourth year of the Public Lecture Series!

March 18- 8pm
Earthquake Conversations - Ross Stein, USGS Menlo Park

For decades, we dreamed of being able to divine the time and place of the world’s next disastrous shock. But by the early 1980s most of us concluded that the planet’s largest tremors are isolated, random and utterly unpredictable. Once a major earthquake and its aftershocks do their damage, the fault will remain quiet until stresses in the earth’s crust have time to rebuild, and the earthquake will have little effect on other faults. But a new hypothesis, termed earthquake stress triggering, is beginning to overturn that assumption. Faults are seen instead to be unexpectedly responsive to subtle stresses they acquire as neighboring faults shift and shake. Although there are dissenting and competing views, stress triggering may well explain the outstanding features of seismicity, including the distribution and decay of aftershocks, the occurrence of earthquake sequences, and seismic quiescence.

May 27- 8pm
Finding Fault in LA - Susan Hough, USGS Pasadena

You know that you live in Earthquake Country, but are you really aware of your faults? Do you know where they are, and how they have shaped the landscape? Do you know where the 1971 Sylmar earthquake left fault breaks at the surface, and where evidence of this earthquake can still be seen today? Come take a tour of some of Los Angeles' more conspicuous faults, including the Raymond and Sierra Madre faults close to Pasadena and faults that run alongside some of Los Angeles' most famous attractions. This talk will begin with an overview of the geologic setting in Southern California--why faults exist in the first place--but will focus on a visual tour of faults in their native habitats. The talk will also cover some of the fault-finding opportunities that present themselves along the drives to Las Vegas and Mammoth Lakes. If you think of Highway 395 as a long and dull drive to ski country, come find out why, geologically speaking, it is anything but boring.