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!

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Do solar flares or magnetic storms (space weather) cause earthquakes?

Solar flares and magnetic storms belong to a set of phenomena known collectively as "space weather". Technological systems and the activities of modern civilization can be affected by changing space-weather conditions. However, it has never been demonstrated that there is a causal relationship between space weather and

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Can some people sense that an earthquake is about to happen (earthquake sensitives)?

There is no scientific explanation for the symptoms some people claim to have preceding an earthquake, and more often than not there is no earthquake following the symptoms.

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Can the ground open up during an earthquake?

Shallow crevasses can form during earthquake-induced landslides, lateral spreads, or from other types of

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Will California eventually fall into the ocean?

No, California is not going to fall into the ocean. California is firmly planted on the top of the earth’s crust in a location where it spans two tectonic plates. The San Andreas Fault System, which crosses California from the Salton Sea in the south to Cape Mendocino in the north, is the boundary between the Pacific Plate

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Is there earthquake weather?

In the 4th Century B.C., Aristotle proposed that earthquakes were caused by winds trapped in subterranean caves. Small tremors were thought to have been caused by air pushing on the cavern roofs, and large ones by the air breaking the surface. This theory lead to a belief in earthquake weather, that because a large amount

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Can animals predict earthquakes?

The earliest reference we have to unusual animal behavior prior to a significant earthquake is from Greece in 373 BC. Rats, weasels, snakes, and centipedes reportedly left their homes and headed for safety several days before a destructive earthquake. Anecdotal evidence abounds of animals, fish, birds, reptiles, and insects

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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?

A temporary increase or decrease in seismicity is part of the normal fluctuation of earthquake rates.  Neither an increase or decrease worldwide is a positive indication that a large earthquake is imminent.

The ComCat earthquake catalog contains an increasing

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Can "MegaQuakes" really happen? Like a magnitude 10 or larger?

No, earthquakes of magnitude 10 or larger cannot happen.  The magnitude of an earthquake is related to the length of the fault on which it occurs. That is, the longer the fault, the larger the earthquake. A fault is a break in the rocks that make up the Earth's crust, along which rocks on either side have moved past each

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Can you predict earthquakes?

No. Neither the USGS nor any other scientists have ever predicted a major earthquake. We do not know how, and we do not expect to know how any time in the foreseeable future. An earthquake prediction must define 3 elements: 1) the date and time, 2) the location, and 3) the magnitude.

Yes, some people

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Date published: March 8, 2018

New 3D Measurements Improve Understanding of Geomagnetic Storm Hazards

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.

Date published: January 3, 2017

Natural Hazards of 2016

Reflecting on 2016 hazards serves as a reminder of the dangers we face and the need for preparedness to save lives and property.

Date published: June 26, 2014

New Audiences, New Products for the National Seismic Hazard Maps

New Audiences, New Products for the National Seismic Hazard Maps

Date published: January 23, 2012

A 100-year-long History of Earthquakes and Seismic Monitoring in Hawaii

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. 

Date published: April 21, 2008

Earthquake Hazard Maps Show How the Nation Shakes with Quakes

Friday's magnitude-5.2 earthquake in southern Illinois is a reminder that earthquakes are a national hazard.

Date published: April 25, 2005

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.

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Image: Deploying Electromagnetic Sensors
March 20, 2016

USGS and Oregon State University scientists deploying electromagnetic sensors in the field.

Resolve 15
2015 (approx.)

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 https://doi.org/10.3133/fs20163075.

Resolve 8
2015 (approx.)

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.

photo of electromagnetic equipment on a sandy beach
November 30, 2000

Electromagnetic Survey 

Image: Northridge, CA Earthquake Damage
January 1, 1994

Collection of USGS still images taken after the January 17, 1994 Northridge earthquake highlighting the damage to buildings and infrastructure.

Chart showing the Earth’s magnetic feild

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 World Geodetic System 1984 ellipsoid.