Earthquake Hazards Program
News
Catalog Shows Complex Rupturing During 2019 Ridgecrest Sequence
The 2019 Ridgecrest earthquake sequence, which startled nearby California residents over the 4 July holiday with magnitude 6.4 and magnitude 7.1 earthquakes, included 34,091 earthquakes overall, detailed in a high-resolution catalog created for the sequence.
As Aftershocks Continue in Puerto Rico, USGS Supports Quake Recovery
A sequence of earthquakes in southwest Puerto Rico continues to affect people living there, with the largest recent aftershock a magnitude 5.2 on Jan. 15. U.S. Geological Survey scientists on the island and the mainland are providing up-to-date scientific information to help the Commonwealth government and the Federal Emergency Management Agency make decisions that protect the public.
Earthquake Scenarios for Puerto Rico
Earthquakes are unsettling, destructive, and often tragic to the communities they affect. The USGS works diligently to help keep people safer by providing them and their emergency responders the science needed to respond to ongoing hazards.
Last updated January 26, 4:30pm Pacific time, 2020.
(The next update will be on January 29, 2020.)
Escenarios de terremotos en Puerto Rico
Los terremotos, como los ocurridos en Puerto Rico, pueden ser preocupantes, destructivos y en muchas ocasiones trágicos para las comunidades afectadas.
Última actualización el 26 de enero, 4:30 p.m., hora del Pacífico, 2020.
(La próxima actualización será el 29 de enero de 2020).
Magnitude 6.4 Earthquake in Puerto Rico
Links to forecasts and scenerios (below) will continue to be updated, however, text in this story will not be updated unless there is significant change to the aftershock behavior or to the USGS response to the earthquake.
7-day aftershock forecast [English]
USGS provides update for the National Seismic Hazard Model
USGS experts recently released a study that incorporates the latest earthquake science findings into an update of the National Seismic Hazard Model for the “lower-48” United States. Read the full report here: https://journals.sagepub.com/doi/full/10.1177/8755293019878199
In the Field with Kate Scharer
What’s a day in the life of a research geologist like?
Extending Rupture History in Grand Tetons National Park (SSA News Release)
"19 November 2019–Hand-dug trenches around Leigh Lake in Grand Teton National Park in Wyoming reveal evidence for a previously unknown surface-faulting earthquake in along the Teton Fault—one occurring about 10,000 years ago." A Seismological Society of America news release covers recent research published by USGS scientists and cooperators.
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All Systems Go for First Statewide Testing of ShakeAlert in the United States
Today, the U.S. Geological Survey and the State of California pressed the “go” button to allow the first-ever statewide public testing of the California Early Earthquake Warning System, which is powered by USGS’s earthquake early warning alerts, called ShakeAlerts.
What if the ShakeAlert Earthquake Early Warning System Had Been Operating During the M6.9 1989 Loma Prieta Earthquake?
How will ShakeAlert® likely perform now on a large earthquake impacting a major urban area? How much warning will you get? To answer this, let’s do a thought experiment...
Read the new Science for Everyone article at What if the ShakeAlert Earthquake Early Warning System...
The 2019 Great ShakeOut
When the ground starts to shake, what do you do? Great ShakeOut 2019: Drop, Cover, and Hold On!
New Earthquake Science for Everyone Web Article
The goal of an earthquake early warning (EEW) system is to provide an alert to people and automatic systems after an earthquake begins but before the shaking reaches their location. Two recent studies explored the timeliness and accuracy of alerts.
Read Earthquake Early Warning...