USU Geologists Explore the 'Guts' of Active Fault Zone
Thursday, Feb. 19, 2009
USU geology professor Jim Evans (orange vest) explains fault processes to reporters during a recent visit to a trench at Utah's South Cache Fault. Evans was a featured speaker at the 2009 American Association for the Advancement of Science meeting.
Goldwater Scholar Tamara Jeppson is among students involved in Evans' research with the NSF-funded SAFOD project. Jeppson, an undergraduate geology and physics major, is studying how earthquake energy is partitioned along the San Andreas Fault.
Utah State University geologist James “Jim” Evans is among a group of researchers peering deep into California’s San Andreas fault to explore previously unseen geophysical phenomena. He was a featured speaker at the 2009 meeting of the American Association for the Advancement of Science held Feb. 12-16 in Chicago.
Evans, currently on sabbatical at the University of Wisconsin, Madison, is an investigator for the San Andreas Fault Observatory at Depth — SAFOD — project. Launched in 2003, SAFOD is one of three major components of EarthScope, a National Science Foundation-funded initiative being carried out in collaboration with the U.S. Geological Survey to probe powerful geological forces that shape the North American continent. SAFOD is the first subterranean earthquake observatory established directly within a seismically active fault.
At a Feb. 15 press conference, Evans told reporters that researchers have drilled nearly 11,500 feet into the fault to install instruments in hopes of “really getting into the guts of the fault zone” to record an earthquake.
“We’ve drilled into earthquakes,” Evans says. “For one of the first times we can look at rocks in a zone where we know earthquakes occur.”
In the curved borehole lined with steel and concrete, SAFOD scientists have inserted a variety of instruments and sensors that provide round-the-clock measurement of temperature, fluid pressure, strain accumulation and other processes.
With undergraduate and graduate students, Evans is collecting data at the site to gain insights into fault zone properties.
“One of the primary objectives of the SAFOD project is to determine the structure and composition of the active San Andreas Fault zone at depths where earthquakes nucleate,” he says.
Evans and colleagues caution that their current research, while offering a literal window deep within the Earth, does not yet yield the tools and information to predict the next big one.
“Even so, we’re able to observe the actual earthquake machine in real-time,” he says.
In related activities, USU’s Geology Department hosts geologist Greg Hirth of Brown University, who presents “Understanding Earthquake Processes at the Microscopic Scale” Monday, Feb. 23, from 11 a.m.-noon in the Taggart Student Center auditorium. His talk is free and open to all.