SCEC Scientists Cross Boundaries to Better Understand Earthquakes in L.A. and Beyond
By Eva Emerson
Home to half of all the earthquake risk in the United States, Southern California rests on a web of geographic faults that form an ideal seismic laboratory. The active fault network, naturally defined by its geology and geography, forms a useful unit for scientific research. “If you study earthquakes, Los Angeles is the place to be,” says Tom Jordan, the W. M. Keck Foundation Chair in Geological Sciences at USC College.
Jordan walks his talk. A distinguished geophysicist, he left his position at the Massachusetts Institute of Technology (MIT) a few years ago to become director of the Southern California Earthquake Center (SCEC), a multi-institutional research organization headquartered at the College. In the dozen years since it began, SCEC has become the largest university-based center for the study of earthquakes and the hazards they pose throughout the country.
“What we do here is to bring people together from many different disciplines to come up with better ways to study earthquakes and predict their effects,” says Jordan. In many ways, the center’s virtual research community has become an experiment in itself, testing ideas on how scientists can work together to answer society’s most pressing questions.
Center Without Walls
SCEC may be based at USC, but it is truly a center without walls, composed of 14 core institutions—USC, Caltech, UCLA, Stanford University, Harvard University, MIT, UC Santa Barbara, UC San Diego, San Diego State University, Columbia University, the University of Nevada-Reno and three offices of the U.S. Geological Survey (USGS). Another 30 research organizations participate as affiliate members, with many more individuals from around the world working on specific projects.
Beyond its basic research, the center works to integrate data into a comprehensive, physics-based understanding of earthquakes and to communicate its findings to the public, educators and key stakeholders. SCEC efforts have advanced what is known of the region’s dynamic geology, the effects of earthquakes on buildings, planning an emergency response and how Southland citizens can best prepare for a disastrous temblor.
Thomas Henyey, professor of earth sciences and deputy director of SCEC, credits the center’s successes to its ability to combine the knowledge, talents and efforts of seismologists, geologists, geochemists, physicists, mathematicians and others. “Through interdisciplinary interactions, SCEC research is at the frontier of characterizing the physical phenomenon of an earthquake, what we call the hazard,” Henyey says. Understanding the hazard is a fundamental piece of mitigating seismic risk—the losses of life and property caused by earthquakes.
Although SCEC, which is supported by grants from the National Science Foundation (NSF) and USGS totaling $5.9 million per year, focuses particularly on Southern California, “we can translate what we do here into knowledge that is valuable to people all over the world,” says Jordan.
Earth’s Complex Behaviors
Driven by the motion and collision of the planet’s tectonic plates, earthquakes occur along faults in the earth’s crust when mounting tension becomes too great. Yielding to the intensity of the built-up tension, the sides of the fault suddenly slip past each other (in a motion that is similar to snapping one’s fingers) and release energy in waves that travel through the crust to the surface and cause the ground to shake. “Earthquakes are a behavior of the earth that emerges from a very complex set of interactions deep underground and at the surface,” Jordan says.
SCEC researchers have focused on identifying and characterizing local fault systems and analyzing how strong ground motions generated by earthquakes are transmitted through rock formations and sediments. For example, they have shown that a site on a rocky hill tends to shake less than one at the bottom of a sediment-rich valley, even if the sites are the same distance from the epicenter of an earthquake. The softer, more shifting sediments and soils can actually amplify seismic waves, leading to greater shaking at the surface. Using this information and other data, SCEC scientists have produced maps revealing Los Angeles’ seismic hot spots—areas prone to more intense shaking due to underlying geology or proximity to an active fault.
Another core aspect of SCEC’s research program is a seismic network composed of 250 Global Positioning System (GPS) stations distributed throughout the Los Angeles basin. The GPS units can detect slight changes in position, providing a measure of strain accumulation and release, and key data for regional earthquake models.
Problems With Prediction
The Regional Earthquake Likelihood Models (RELM), first created by SCEC in 1995, have been among the center’s most significant contributions to science and society. “We keep trying to build a better model for L.A. that will tell us where the worst earthquakes will occur. The more difficult problem is knowing when,” Jordan says. “We will probably never be able to accurately predict an earthquake within days or weeks of an event.”
Yet, scientists at SCEC and elsewhere have made progress on long-term estimates of how often, on average, a particular fault will slip and trigger an earthquake. These estimates are on the order of every 100 to 1,000 years.
In the future, Jordan speculates it might be possible to begin predicting earthquakes at an intermediate time scale of months to decades. “Even intermediate prediction is dicey in terms of whether it will work. We’re not sure,” he says.
Creating a Collaboratory
“Information technology is an increasingly important part of the infrastructure of all scientific research. SCEC, for example, is a truly distributed community, and we need strong information sciences tools to collaborate effectively on our research,” Jordan says.
Funded by a $10 million NSF grant, SCEC has partnered with other leading earthquake and information technology centers to create an online collaborative laboratory, or collaboratory, for the study of earthquakes. The Community Modeling Environment aims to increase the efficiency of online collaborations. Computer grid technology, developed at the USC Information Sciences Institute, will provide SCEC with the massive processing capabilities needed to do state-of-the-art earthquake research.
Among other goals is the creation of a digital library to make the vast store of accumulated earthquake data accessible to all. SCEC’s partners on this project include the USC Center for High Performance Computing and Communications, the San Diego Supercomputer Center, the Incorporated Research Institutions for Seismology and the USGS.
It Takes a Village
“We are in an era of extremely rapid change in how the scientific enterprise works,” Jordan says. “There’s a new appreciation of the value of doing systems science. It turns out that we know how to do things together that we, as individual scientists, can’t do alone. It takes a village, so to speak, to make these things happen.”
Systems-level work is one of the next big things in science, many scientists believe. They point to SCEC, the USC Neuroscience Program and the USC Wrigley Institute for Environmental Studies as prime examples of how this kind of approach allows scientists to ask bigger questions about the natural world, whether about the human brain, global climate change, or—closest to Jordan’s heart—the planet’s hidden interior and awesome movements.
Jordan cautions that building SCEC’s earthquake community has not been quick or easy. Doing creative interdisciplinary research takes longer, as collaborators learn about new fields and approaches. “Working together to learn something can make things harder, because academia rewards you for how well you stand out from the crowd, not how well you fit in,” he says.
Yet fitting in as a part of a team may well be where the future of scientific investigation lies. “I’m willing to wager that in the future, places like SCEC will be the model of how collaborative projects are organized in universities,” Jordan says. “We’re changing the structure of science.”
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