Due to a lapse in appropriations, the majority of USGS websites may not be up to date and may not reflect current conditions. Websites displaying real-time data, such as Earthquake and Water and information needed for public health and safety will be updated with limited support. Additionally, USGS will not be able to respond to inquiries until appropriations are enacted. For more information, please see www.doi.gov/shutdown
Are earthquakes associated with variations in the geomagnetic field?
Electromagnetic variations have been observed after earthquakes, but despite decades of work, there is no convincing evidence of electromagnetic precursors to earthquakes. It is worth acknowledging that geophysicists would actually love to demonstrate the reality of such precursors, especially if they could be used for reliably predicting earthquakes!
Learn more: USGS Geomagnetism Program
Why are we having so many earthquakes? Has naturally occurring earthquake activity been increasing? Does this mean a big one is going to hit? OR We haven't had any earthquakes in a long time; does this mean that the pressure is building up for a big one?
Measurements of the three-dimensional structure of the earth, as opposed to the one-dimensional models typically used, can help scientists more accurately determine which areas of the United States are most vulnerable to blackouts during hazardous geomagnetic storms.
Reflecting on 2016 hazards serves as a reminder of the dangers we face and the need for preparedness to save lives and property.
New Audiences, New Products for the National Seismic Hazard Maps
The Hawaiian Volcano Observatory’s 1912–2012 Centennial—100 Years of Tracking Eruptions and Earthquakes
HAWAI‘I ISLAND, Hawaii —The history of earthquakes and seismic monitoring in Hawai‘i during the past century will be the topic of a presentation at the University of Hawai‘i at Hilo on Thursday, January 26, at 7:00 p.m.
Friday's magnitude-5.2 earthquake in southern Illinois is a reminder that earthquakes are a national hazard.
Are You Safe When A Natural Hazard Strikes? Learn How Science Can Help Reduce the Risk of Loss of Life and Property When Natural Hazards Occur
Reston, VA – More Americans are at risk from being severely impacted by natural hazards now than any other time in our nation’s history.
USGS and Oregon State University scientists deploying electromagnetic sensors in the field.
A low-flying helicopter will carry this large cylindrical sensor, called a bird, to measure physical properties of the Big Sioux aquifer below the Earth's surface. More information on the airborne electromagnetic method is available at https://doi.org/10.3133/fs20163075.
Airborne electromagnetic data collection over an agricultural field near Sioux Falls, SD. The bird is suspended from a helicopter as it transmits and receives electromagnetic signals to the ground, which are used to interpret characteristics of the aquifer. More information on the airborne electromagnetic method is available at...
This is one of five world charts showing the declination, inclination, horizontal intensity, vertical component, and total intensity of the Earth’s magnetic field at mean sea level at the beginning of 2005. The charts are based on the International Geomagnetic Reference Field (IGRF) main model for 2005 and secular change model for 2005-2010. The IGRF is referenced to the...