New UCI Research Will Have You Looking at Earthquakes and Lawns Differently
|UCI and ASU researchers dug trenches across the San Andreas fault in the Carrizo Plain, about 100 miles northwest of Los Angeles, to study large earthquakes.|
Lisa Grant Ludwig, associate professor of public health at UCI, led a research team composed of Anteaters and Sun Devils (Arizona State University) that established the age of a few dry stream channels with bends created by the San Andreas fault in the Carrizo Plain near Bakersfield. The team then determined how many earthquakes had occurred after the formation of each channel and approximately how much the fault had moved in each quake.
"The distance that a fault 'slips,' or moves, during a large earthquake reveals a lot about the mechanics of faults," Ludwig says in a UCI.edu feature by Tom Vasich of University Communications. "Getting slip measurements from past earthquakes is like getting a look under the hood of a car--it tells you a lot about the engine."
Looking under the hood revealed something unexpected: Fault slip varied from earthquake to earthquake instead of recurring in a uniform manner, as had been believed.
"The idea of slips repeating in characteristic ways is very appealing, because if you can figure that out, you're on your way to forecasting earthquakes with some reasonable confidence," Ludwig says in the piece. "But these results show that we don't understand the San Andreas fault as well as we thought we did."
Results of the study, to be published online Jan. 21 at Science Express, show the amount of slip that has built up along the San Andreas fault in the Carrizo Plain matches that of the last "big one" to strike there in 1857, suggesting a similarly large earthquake could be coming to the region.
You're welcome, Carrizo Plainers!
"The recent disaster in Haiti is a reminder that a destructive quake can strike without warning," Ludwig says. "One thing that hasn't changed is the importance of preparedness and earthquake-resistant infrastructure in seismically active areas around the globe."
Earth system science postdoctoral researcher Amy Townsend-Small's study, which is to be published in the journal Geophysical Research Letters, finds total greenhouse gas emissions would decrease--in Southern California, at least--if lawns did not exist here at all.