Earthquake Science and Engineering

When Caltech’s Nadia Lapusta creates computer models of earthquakes, she must integrate an astonishing range of data—on scales from thousands of kilometers down to microns and from millennia down to thousandths of a second. That’s because to understand the big and slow, she needs to understand the tiny and fast. “Large-scale earthquake ruptures—even those around 8 on the Richter scale—are ultimately happening in very narrow layers of granulated rock,” she says. In fact, where one side of a fault moves against the other, those layers are powdered so thin that a stack of a thousand grains would equal the thickness of a credit card. And although a fault can go eons between destructive quakes, the first slip that kicks off the shaking can take place in a blink.

The 2011 Japanese earthquake was a defining moment for Mark Simons. The devastating 9.0-magnitude quake and its subsequent tsunami, which took nearly 16,000 lives, spurred efforts around the globe that will shape how nations predict and prepare for future natural disasters and motivated new approaches to basic earthquake science that are applicable to seismic events large and small.