A devastating earthquake in Chile last year may have set off a swarm of smaller quakes as far away as California, U.S. researchers reported on Friday.
They found evidence that the magnitude 8.8 quake in Chile, which killed 500 people and set off tsunamis that devastated coastal cities in February, set off a chain of events 6,200 miles away.
The quakes in central California started six hours after the quake in Chile, reported Zhigang Peng of the Georgia Institute of Technology and colleagues there and at the U.S. Geological Survey in Menlo Park, Calif.
"In particular, we identify triggered microearthquakes in the Coso Geothermal Field," they reported in Geophysical Research Letters. "This is one of the most seismically active regions in California," they added.
"At least four microearthquakes at shallow depth (under 1.8 miles) in the Coso Geothermal Field were likely triggered by teleseismic waves from the Chile earthquake."
They also noted a cluster of deep, low-frequency earthquakes along the Parkfield-Cholame section of the San Andreas Fault, they reported in Geophysical Research Letters.
Earthquakes set off seismic waves and Peng's team said in this case types known as Love and Rayleigh waves were likely responsible.
