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Earthquake Hazards Program

The USGS monitors and reports on earthquakes, assesses earthquake impacts and hazards, and conducts targeted research on the causes and effects of earthquakes. We undertake these activities as part of the larger National Earthquake Hazards Reduction Program (NEHRP), a four-agency partnership established by Congress.

News

Rapid Response Seafloor Seismology

Rapid Response Seafloor Seismology

Five Years After the Ridgecrest Earthquake Sequence

Five Years After the Ridgecrest Earthquake Sequence

USGS deploys “aftershock kits” to study Whitehouse Station earthquakes

USGS deploys “aftershock kits” to study Whitehouse Station earthquakes

Publications

Global variability of the composition and temperature at the 410-km discontinuity from receiver function analysis of dense arrays

Seismic boundaries caused by phase transitions between olivine polymorphs in Earth's mantle provide thermal and compositional markers that inform mantle dynamics. Seismic studies of the mantle transition zone often use either global averaging with sparse arrays or regional sampling from a single dense array. The intermediate approach of this study utilizes many densely spaced seismic arrays distri
Authors
Margaret Elizabeth Glasgow, Hankui K. Zhang, Brandon Schmandt, Wen-Yi Zhou, Jinchi Zhang

Relatively stable pressure effects and time-increasing thermal contraction control Heber geothermal field deformation

Due to geological complexities and observational gaps, it is challenging to identify the governing physical processes of geothermal field deformation including ground subsidence and earthquakes. In the west and east regions of the Heber Geothermal Field (HGF), decade-long subsidence was occurring despite injection of heat-depleted brines, along with transient reversals between uplift and subsidenc
Authors
Guoyan Jiang, Andrew Barbour, Robert John Skoumal, Kathryn Zerbe Materna, Aren Crandall-Bear

Uncertainty in ground-motion-to-intensity conversions significantly affects earthquake early warning alert regions

We examine how the choice of ground‐motion‐to‐intensity conversion equations (GMICEs) in earthquake early warning (EEW) systems affects resulting alert regions. We find that existing GMICEs can underestimate observed shaking at short rupture distances or overestimate the extent of low‐intensity shaking. Updated GMICEs that remove these biases would improve the accuracy of alert regions for the Sha
Authors
Jessie Saunders, Annemarie S. Baltay, Sarah E. Minson, Maren Böse