[Rockhounds] New Earthquake Math Predicts How Destructive They’ll Be

[Kreigh Tomaszewski]

When a fault slips, it unleashes a torrent of seismic waves, not all of
them alike. Long low-frequency waves can travel far from their source and
cause tall structures like skyscrapers to sway, while high-frequency waves
are excellent at shaking houses and bridges and reducing them to rubble.
For much of the past half-century, seismologists have assumed that the
frictional slippage of a fault generates this entire seismic suite.

Now a pair of geoscientists from Brown University have conjured up their
own origin story. Using mathematical models inspired by landslides and
avalanches, the researchers argue that these damaging high-frequency waves
are caused not by the slippage itself, but by geological pinball games
taking place within the fault.

“What they’ve done here is pretty neat,” said Elizabeth Cochran, a
seismologist at the U.S. Geological Survey. “I certainly wouldn’t have
thought to represent a fault in the way that they have.”

The new model, published last month in Geophysical Research Letters, still
needs to be tested on future quakes, to see if it accurately predicts their
properties. But if corroborated, it would upend our understanding of
earthquakes’ capacity for destruction and perhaps save lives in the process.

https://www.quantamagazine.org/new-earthquake-math-predicts-how-destructive-theyll-be-20200421/