Earthquake Hazards Program

Early on the morning of August 24, 2014, Loren Turner was awoken by clattering window blinds, a moving bed, and the sound of water splashing out of his backyard pool. He experienced what is now named the “South Napa Earthquake.” 

Which U.S. State or territory has more large earthquakes than the rest of the United States combined?

Geologists have discovered evidence that unusual seas detached living corals from a Caribbean reef and scattered them far inland, as boulders, during the last centuries before Columbus arrived. The new findings will reinforce precautions against coastal hazards, Caribbean tsunami specialists said.

Small variations in the density of the earth’s crust—undetectable to humans without sensitive instruments—influence where earthquakes may occur in the central United States. These new findings from the U.S. Geological Survey, published today in Nature Communications, may allow scientists to map where future seismicity in the center of the country is most likely.

The U. S. Geological Survey is seeking volunteers to host temporary seismic stations in the Walnut Creek/Pleasant Hill/Concord California area. Volunteers will be assisting with a new ground motion study that will begin in March 2017.

What is causing most of the induced earthquakes (aka man-made earthquakes) we’ve seen recently in the central United States?

A new study from the USGS suggests that some early 20th century earthquakes in southern California might have been induced (man-made) by past practices that were used by the oil and gas industry.

A magnitude 6.6 earthquake struck Italy on October 30, 2016 at 06:40:19 UTC (7:40 am local time). This is reportedly the largest earthquake in Italy since the magnitude 6.9 Irpinia earthquake struck southern Italy in 1980. 

A magnitude 6.1 earthquake struck Italy on October 26, 2016 at 19:18:08 UTC (9:18 pm local). A magnitude 5.5 earthquake struck earlier at 17:10:37 UTC. Numerous smaller aftershocks have also occurred.

Distant wastewater disposal wells likely induced the third largest earthquake in recent Oklahoma record, the Feb. 13, 2016, magnitude 5.1 event roughly 32 kilometers northwest of Fairview, Oklahoma. These findings from the U.S. Geological Survey are available in the online edition of Geophysical Research Letters.

True or false? The same size earthquake will cause damage over a larger area in the West than the East.