EarthquakesNew simulations show potential impact of major quakes by building location, size

Published 29 June 2018

With unprecedented resolution, scientists and engineers are simulating precisely how a large-magnitude earthquake along the Hayward Fault would affect different locations and buildings across the San Francisco Bay Area. Researchers are leveraging powerful supercomputers to portray the impact of high-frequency ground motion on thousands of representative different-sized buildings spread out across the California region.

With unprecedented resolution, scientists and engineers are simulating precisely how a large-magnitude earthquake along the Hayward Fault would affect different locations and buildings across the San Francisco Bay Area.

A team from Lawrence Berkeley National Laboratory (Berkeley Lab) and Lawrence Livermore National Laboratory, both U.S. Department of Energy (DOE) national labs, is leveraging powerful supercomputers to portray the impact of high-frequency ground motion on thousands of representative different-sized buildings spread out across the California region

LBL says that their work –part of DOE’s Exascale Computing Project–is important to showing how different seismic wave frequencies of ground motion affect structures of various sizes. Lower-frequency ground motion is known to affect larger structures and is easier to replicate by computer simulation. Small structures like homes are more vulnerable to high-frequency shaking, which requires more advanced computing to simulate.

The researchers presented three scientific papers describing their recent simulations at the U.S. National Conference on Earthquake Engineering (NCEE), a meeting held every four years by the Earthquake Engineering Research Institute. One simulation was run last week using the Cori supercomputer at Berkeley Lab’s National Energy Research Scientific Center (NERSC) to simulate high-frequency (5-hertz) ground shaking.

David McCallen, a senior scientist in the Earth and Environmental Sciences Area at Berkeley Lab, explains that their simulations allow scientists to gain a more realistic picture of the impact that a major earthquake would have on a region.

“Historically, seismic experts have used empirical evidence from previous earthquakes to assess earthquake hazard and risk at regional scale,” said McCallen. “While important, data about ground motion characteristics and resulting structural damage extrapolated from an earthquake that occurred halfway across the world are only so helpful to improving our understanding of how well our California infrastructure could endure seismic stress.”

At the NCEE conference which took place in Los Angeles this past week, the team described recent simulation advancements indicating that event magnitude and ground displacement are positively correlated; that two buildings with the same number of stories 2.4 miles apart and equidistant to the fault line could suffer damages to a far different degree; and that three-story buildings are less sensitive than 40-story buildings to the significant increase in long-period ground motion (exceeding 1 second) that would accompany a large-magnitude earthquake.