Predicting Earthquakes

There’s an interesting new earthquake study getting some press. A group of researchers at Stanford University have developed a new way of predicting ground movement and hazards associated with shaking buildings during earthquakes. They’re using the ambient seismic field, which is generated by ocean waves interacting with the Earth’s crust. The ambient seismic field is always present in the ground, and in the past has been treated a little like interference when studying earthquakes — i.e., the constant small waves of the ambient field had to be sorted out from the larger waves of the seismic shifts that produce earthquakes. In this new technique, the scientists use these smaller waves to help understand how seismic waves move through the ground. From there, they worked out predictions concerning what would happen if much stronger waves occurred, including the way waves are amplified as they move through sediments as well as where they will travel once a seismic event occurs. Since many of our major population areas are in both earthquake-prone and built on top of sedimentary basins (i.e., Tokyo, Mexico City, Seattle, parts of the San Francisco Bay area, and still others), this research may provide valuable insight into what may happen during an earthquake event in those places. Apparently, this technique is not expensive, and so the scientists are also hoping that developing countries, which may not be able to afford the expensive computers needed for other earthquake prediction techniques, will also be able to use it in their planning.

From the policy perspective, this is exciting because it gives us a way to predict (i.e., develop our best guess) about what would happen during an earthquake in various locations. That, in turn helps us plan, develop and build. This sort of research also provides us with ideas about how to prepare in the event of an earthquake, including developing evacuation routes, food storage, and so forth. While the technique is new, researchers will be testing their results in other settings, so we should have a sense of the limitations as well as the possibilities for using it in the near future.

Unfortunately, the Science article is gated, but there is a very nice summary of the findings and their implications in Science Daily.

And for readers with access to Science, here’s the full citation and a link to the article: 

M.A. Denolle, E.M. Dunham, G.A. Prieto, G.C. Beroza. “Strong Ground Motion Prediction Using Virtual Earthquakes.” Science, 2014: 343 (6169): 399 DOI: 10.1126/science.1245678.