What a week! First, an unprecedented winter storm now an earthquake!
The big question everyone is asking today, is this rare for South Carolina to have earthquakes? The answer is no, not at all. The crazy thing is having an earthquake after this huge winter storm we’ve just been through…by the way, there is NO relation to the winter storm and the earthquake however, Mother Nature’s timing is simply hilarious! The fact is one of our nations most damaging quakes took place in Charleston (7.3 magnitude) in 1886 destroying nearly the entire city.
What Is An Earthquake?
Let me give you the Readers Digest version. An earthquake is essentially a vibration inside the Earth that produces shock waves resulting from a sudden movement along a fault line (more on that in a second) the energy released in the quake moves in waves outward in widening circles. It’s like when you throw a rock in a pond and you see the ripples…the strongest “ripple” is near the center and it moves out from there. The center of the “ripple” is called the epicenter, which is directly above the focus of the earthquake.
The “Weather” (what’s happening in the atmosphere at this point in time) is always moving and changing, we can easily see and study the atmosphere however, the earth itself is also moving and changing, we just can’t see that happening like we can the atmosphere.
The solid part of the Earth is called the “Lithosphere,” it’s the inorganic part of the Earth comprising of the crust, minerals, rocks, bedrocks and all types of landforms. The continents have moved, collided, merged and have been torn apart over millions of years, this still continues today. Believe it or not, it’s only been in the last 50 years or so that scientist have come to understand how all this actually happened. There is undeniable evidence to support the movement of “plates” in the earth, these plates are moving the continents. There are 16 different “plate” boundaries around the earth, they are movin and groovin VERY slowly…we’ll get into all of that some other blog.
A “Fault” is a breaking apart of the Earth’s rock structures. There are a number of different types of faults and they are located all over the Earth. Faulting takes place along a weakness in the crust of the Earth. The “Crust” of the earth varies. Over land goes down about 40 miles over the oceans about 4 to 5 miles. The weakness is called a fault zone and where the breaking of the rock structure meets is called a fault line. It’s the movement of the crust along the fault zone that can produce a sudden rupture…the earthquake.
South Carolina and the entire east coast has numerous small and deeply buried faults. Our faults are not like those out west closer to plate boundaries, there, they can name the faults (San Andreas is a good example) earthquakes out west happen more frequently. The type of soil plays a factor in whether or not you feel an earthquake. South Carolina is located on bedrock where places such as the Ohio Valley, known for earthquakes (New Madrid Fault) the soil is loose and sandy.
The cause of our earthquake? Several theories are coming out. I would say it has more to do with our relation to the Appalachian Mountain chain. It could easily be some break in sedimentation and rocks that caused the Earth to “move” at the point under Edgefield.
SOUTH CAROLINA FAULT LINES: