Video: How Well Can We Predict Earthquakes?
But researchers noticed that these models assumed that seismic waves moved through rigid rock. In a large earthquake, rocks can only take so much shaking before they break, absorbing some of the earthquake's energy.
Also, the properties of the rock between the epicenter and Los Angeles determine how much earthquake energy reaches Tinseltown. Less seismic energy travels through a less-cohesive material such as loose sand than through a highly-cohesive rock such as solid granite.
Could LA Quake Mean the End of a Seismic Drought?
Taking these factors into account, the team re-modeled a large earthquake in Southern California, using realistic ranges for rock cohesion in the region. Their results, published in Geophysical Research Letters, show that the sediments in the seismic-wave-amplifying valleys absorbed some of the earthquake's energy.
If true, that could mean much less shaking for the 18 million residents of the Los Angeles area.
Photo: A magnitude 7.2 earthquake struck this embankment in Calexico, Calif. on Easter Sunday 2010 fracturing the hillside. Credit: Adam DuBrowa/FEMA