Earthquakes

Release Date: JULY 6, 2020 In 1722 and 1723 a London clockmaker, George Graham, observed daily and consistent variations on one of his instruments, a “Needle upon the Pin” (a compass), for which he had no explanation. Swedish scientists obtained some of Graham’s instruments to record what is now known to be the variations in Earth’s magnetic field. In 1741, they noticed a significant deflection of...

Release Date: MAY 29, 2020 Residents in California, Oregon, and Washington have been told that earthquake early warning (EEW) is at their doorstep and will alert them to the shaking from an earthquake before it arrives. Some media reports have said there will be “up to a minute of warning”. The problem is, for onshore earthquakes these claims are exaggerated, and under some conditions a warning is...

The USGS uses computer simulations to evaluate the physical relationships between fluid injection (or extraction) and earthquakes. We can only indirectly study these relationships using observations, so computer simulations help us gain a better physical understanding for the processes that are most likely causing these earthquakes. Scientists can also use such simulations to understand complex...

In 2016, 2017, and 2018, the USGS released induced earthquake hazard models. These models forecast the expected strength and frequency of potential ground shaking from future induced and natural earthquakes for a one-year period, based primarily on earthquake data from the previous year. Areas of high induced earthquake hazard were identified in Oklahoma-southern Kansas, the Raton Basin (CO/NM...

Seismicity catalogs, gridded seismic hazard curve data, gridded ground motion data, and mapped gridded ground motion values are available for the 2002 National Seismic Hazard Model for the Conterminous U.S. Seismicity catalogs are available for the western U.S. (in Mw) and central and eastern U.S. (in mb).

Seismicity catalogs, GIS shapefiles, gridded seismic hazard curve data, gridded ground motion data, and mapped gridded ground motion values are available for the 2014 National Seismic Hazard Model for the Conterminous U.S.

Seismicity catalogs, gridded seismic hazard curve data, gridded ground motion data, and mapped gridded ground motion values are available for the 2008 National Seismic Hazard Model for the Conterminous U.S.

Seismicity catalogs, gridded seismic hazard curve data, gridded ground motion data, and mapped gridded ground motion values are available for the 1996 National Seismic Hazard Model for the Conterminous U.S. Seismicity catalogs are available for the western U.S. (in Mw) and central and eastern U.S. (in mb).

U.S. National Seismic Hazard Model for the State of Hawaii defines the potential for earthquakes and ground shaking. The original model was competed in 1998 (published in 2001) and recently updated in 2021.

Shortly after the Great San Francisco earthquake of April 18, 1906, a sea level disturbance (tsunami) was recorded at the Presidio tide gauge station in San Francisco (the station is now located nearby at Ft. Point). What type of mechanism (earthquake rupture, landslide, other) generated the tsunami recorded at the Presidio tide gauge station?

Our tsunami scientists work on international teams to study the aftermath of tsunamis around the world, to gain a better understanding the impact of potential tsunamis on coastal communities of the United States. Their work helps inform local, state, and federal coastal planning, protection, and resiliency.

Selected geophysical data for research.