Trying to figure out why in the Eastern part of USA sometimes recorded until recently unexplained seismic tremors, experts from the University of North Carolina at chapel hill ran into a very unusual natural phenomenon. As it turned out, in some parts of the territory under the crust literally breaks away from the mantle. In the long term it may cause more severe earthquakes, the researchers said.
The Eastern part of the United States of America is on a stable tectonic plate, and on the middle and not at the junction with the other. This should mean that earthquakes for the region should be extremely uncharacteristic. In practice, however, observe a weak but noticeable tremors in this area, seismologists recorded quite often. To find out why this is happening, experts have created three-dimensional computer model showing the earth’s crust and upper mantle under the United States. Data were collected with the help of images taken in x-rays, reports livescience.com.
As it turned out, the thickness of the crust beneath the cities in the Eastern United States (including Washington, capital of the state), has been extremely uneven and, in all likelihood, these irregularities and trigger small earthquakes. According to researchers, the cause of such features could serve as a process of detachment of the crust from the mantle. That process is running, most likely, was 65 million years ago, when some tectonic plates, including scientists have investigated turned out to be deformed due to the collision with each other.
In all likelihood, in the future, tremors can occur more often and become slightly more tangible. However, truly catastrophic consequences of the separation of the crust from the mantle in the foreseeable future, experts urge not to expect: geological processes similar to the observed flow in the earth’s crust is extremely slow and require tens of millions of years, so that even the grandchildren of the present residents of the Eastern part of the US and their grandchildren are unlikely to face strong earthquakes in this territory.Related posts: