By Tim Gardner
If you were in Avery County Monday morning and felt something tremble and sake for a few seconds, it wasn’t your imagination. At 7:00 a.m., the United States Geological Survey detected an earthquake in the Northwest Avery County town of Elk Park.
The USGS listed the earthquake as only 7.8 kilometers in depth and 2.0 in magnitude.
According to scientists, the cause of an earthquake is simple. The surface of the Earth is in continuous slow motion. This is plate tectonics–the motion of immense rigid plates at the surface of the Earth in response to flow of rock within the Earth. The plates cover the entire surface of the globe. Since they are all moving they rub against each other in some places, sink beneath each other in others or spread apart from each other.
At such places the motion isn’t smooth–the plates are stuck together at the edges but the rest of each plate is continuing to move, so the rocks along the edges are distorted or strained. As the motion continues, the strain builds up to the point where the rock cannot withstand any more bending. With a lurch, the rock breaks and the two sides move.
In conclusion, an earthquake is the shaking that radiates out from the breaking rock