Researchers in Loyola Marymount University’s Mechanical Engineering Department are working to identify characteristics of intershocks—the smaller shocks before and after a quake—with the future aim of being able to forecast earthquakes much like meteorologists forecast the weather.
Natalie Schaal, assistant professor of mechanical engineering in the LMU Frank R. Seaver College of Science and Engineering, acknowledges they’re a long way from being able to forecast when quakes will occur. And Junheng (Carl) Li, a senior in mechanical engineering who’s been working with Schaal on the effort since the fall of 2018, said “Earthquake forecasting remains a mysterious topic, yet one with powerful implications.”
Predications about earthquakes today are based on statistical probabilities. Schaal and Li are interested in understanding the physics involved in earthquakes that will help in forecasting down the line.
The sources of earthquakes typically lie between tens to hundreds of kilometers beneath the earth’s surface, making this a particularly challenging enterprise.
Schaal and Li have analyzed data from complex computer simulations of heterogeneous fault behavior and have tagged the increasing physical size of the rupture as a characteristic that may precede a large quake. But at this stage, everything’s preliminary.
“Relative rupture size is our main candidate to say that a big earthquake is coming,” said Schaal. “We need to be able to tell the difference between the intershocks that lead to a bigger earthquake and those that don’t.”
There’s no standard method for conducting this type of research and Schaal says she and Li have been developing one. Li presented the results of their efforts at the Engineering Mechanics Institute Conference in June 2019 and at the Southern California Earthquake Center’s Annual Meeting in September.
Li spent his summer working on this project titled “Investigation of the Time-Dependence of Intershock Properties and Potential Consequences for Earthquake Forecasting” in Seaver’s Summer Opportunities for Advanced Research (SOAR) program.
“Carl is from a place in China where earthquakes occur frequently,” said Schaal. “He came to me, asking to be involved in the project.”
“It’s a really great opportunity for me,” said Li. “I wouldn’t have known I wanted to do a master’s or Ph.D. without doing research as an undergraduate. Now, I want to be a professor and do more research.”
Li is on his way to graduate school after he earns his degree at LMU this spring, having already received two acceptances from the four schools to which he applied.
Schaal is collaborating with the University of Toronto Mississauga to run new simulations that can produce more events to continue work on understanding intershock characteristics.