It was a bright sunny day during the autumn of 7th grade. October 17th, 1989 a little after 5 in the afternoon to be precise. My parents were on a trip and I was home alone when the shaking started. I'll never forget the initial confusion and subsequent fear that ensued when the 1989 Loma Prieta Earthquake hit the Bay Area.
That fear probably has something to do with the reason I'm a geologist studying earthquakes today. In addition to this fear is an extreme respect for the complexity and beauty of the natural world.
My specific field of study goes by the name "Active Tectonics" and involves understanding earthquake and fault behavior with the goal of enhancing our ability to characterize seismic hazard. Even with sophisticated tools such as high resolution seismology it is extremely difficult to understand the processes occuring at 5 - 15 km below the surface where earthquake ruptures start. After my first year of graduate school, I realized that there are several tools that can help us figure out how faults behave at depth.
Geodesy is the science of surveying, and precise surveys using the Global Positioning System (GPS) allow us to monitor both fault creep and the elastic buildup of strain near locked faults.
Exhumed faults are exposures of faults that were originally deep below the surface but through uplift and erosion (usually over millions of years) have been brought to the surface. Unlike surface observations of active faults that have limited resolution, exhumed faults can be observed at all scales -- using everything from air photos to microscopes.
Return to Matt's Home Page