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