Slowdown in seismic waves map areas with temblor ingredients: weakened rock, fluid buildup
USGS Earthquake Hazards Program
Rumbling earthquakes could reveal faraway weak spots in Earth’s crust.
Following a 2012 earthquake that rattled Costa Rica, researchers noticed that the quake fractured underground rock tens of kilometers from its epicenter. Before the quake, that fractured region had already been weakened by pressurized fluids mixed in with the rock, the researchers propose online January 8 in Science Advances. Such weakened patches are more prone to shift and set off major earthquakes. So monitoring where future quakes fracture rock will help scientists better understand how the fluids that help spawn earthquakes disperse around Earth’s crust, says study coauthor Esteban Chaves. That could let seismologists better forecast where titanic tremors are likeliest to strike.