A year after the August 23, 2011 Virginia earthquake, USGS geologist Dr. Mike Blanpied discusses whether a similar event could occur again in the region in the near future, and in an earthquake, what you can do to stay stay safe.
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 nor decrease worldwide is a positive indication that a large earthquake is imminent.
The ComCat earthquake catalog contains an increasing number of earthquakes in recent years--not because there are more earthquakes, but because there are more seismic instruments and they are able to record more earthquakes.
The National Earthquake Information Center now locates about 20,000 earthquakes around the globe each year, or approximately 55 per day. As a result of the improvements in communications and the increased interest in natural disasters, the public now learns about earthquakes more quickly than ever before.
According to long-term records (since about 1900), we expect about 16 major earthquakes in any given year. That includes 15 earthquakes in the magnitude 7 range and one earthquake magnitude 8.0 or greater. In the past 40-50 years, our records show that we have exceeded the long-term average number of major earthquakes about a dozen times.
The year with the largest total was 2010, with 23 major earthquakes (greater than or equal to magnitude 7.0). In other years the total was well below the annual long-term average of 16 major earthquakes. 1989 only had 6 major earthquakes and 1988 only had 7.
Learn more: Earthquake Lists, Maps and Statistics
Related
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. USGS scientists can only calculate the probability that a significant earthquake will occur ( shown on our hazard mapping ) in a specific area within a certain number of years. An earthquake prediction must define 3 elements...
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 exhibiting strange behavior anywhere from weeks to seconds before an...
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 other. No fault long enough to generate a magnitude 10 earthquake is known to...
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.
Can the ground open up during an earthquake?
Shallow crevasses can form during earthquake-induced landslides, lateral spreads, or from other types of ground failures, but faults do not open up during an earthquake. An earthquake occurs when two blocks of the earth’s crust slide past one another after having been stuck together in one place for a long time, because of friction on the fault, while the rest of the crust away from the edges has...
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 (that includes the Pacific Ocean) and North American Plate (that includes...
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 of air was trapped underground, the weather would be hot and calm before an...
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 earthquakes. Indeed, over the course of the Sun's 11-year variable cycle, the...
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
A Year After the 2011 Virginia Earthquake: Will Shaking Continue?
A year after the August 23, 2011 Virginia earthquake, USGS geologist Dr. Mike Blanpied discusses whether a similar event could occur again in the region in the near future, and in an earthquake, what you can do to stay stay safe.
A map of ShakeOut scenario shaking in southern California
A map of ShakeOut scenario shaking in southern California.
A map of ShakeOut scenario shaking in southern California.
Why are we having so many earthquakes? Has earthquake activity been increasing?
Listen to hear the answer.
Related
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. USGS scientists can only calculate the probability that a significant earthquake will occur ( shown on our hazard mapping ) in a specific area within a certain number of years. An earthquake prediction must define 3 elements...
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 exhibiting strange behavior anywhere from weeks to seconds before an...
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 other. No fault long enough to generate a magnitude 10 earthquake is known to...
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.
Can the ground open up during an earthquake?
Shallow crevasses can form during earthquake-induced landslides, lateral spreads, or from other types of ground failures, but faults do not open up during an earthquake. An earthquake occurs when two blocks of the earth’s crust slide past one another after having been stuck together in one place for a long time, because of friction on the fault, while the rest of the crust away from the edges has...
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 (that includes the Pacific Ocean) and North American Plate (that includes...
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 of air was trapped underground, the weather would be hot and calm before an...
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 earthquakes. Indeed, over the course of the Sun's 11-year variable cycle, the...
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
A Year After the 2011 Virginia Earthquake: Will Shaking Continue?
A year after the August 23, 2011 Virginia earthquake, USGS geologist Dr. Mike Blanpied discusses whether a similar event could occur again in the region in the near future, and in an earthquake, what you can do to stay stay safe.
A year after the August 23, 2011 Virginia earthquake, USGS geologist Dr. Mike Blanpied discusses whether a similar event could occur again in the region in the near future, and in an earthquake, what you can do to stay stay safe.
A map of ShakeOut scenario shaking in southern California
A map of ShakeOut scenario shaking in southern California.
A map of ShakeOut scenario shaking in southern California.
Why are we having so many earthquakes? Has earthquake activity been increasing?
Listen to hear the answer.