CHARLESTON, S.C. (WCBD) – With recent earthquakes felt in parts of Dorchester County and the Midlands in recent weeks, we look at the history of earthquakes in South Carolina.
READ: 3 Earthquakes hit Ladson in less than a week
Why do earthquakes occur?
An earthquake is caused by the sudden movement of rock beneath the Earth’s surface, often causing violent shaking on top. Earthquakes will happen without warning, as there is no reliable method for predicting when an earthquake will occur.
While we aren’t exactly known for earthquakes, South Carolina is actually the most seismically active state on the East Coast. Officials say 10 to 20 earthquakes are recorded in the state each year, while only two to five are actually felt. It is uncommon for South Carolinians to experience an earthquake with a magnitude higher than 3, but it has happened before.
The majority of earthquakes will occur at a tectonic plate boundary; these are known as interplate earthquakes. South Carolina lies within the North American plate, far from any plate boundary, so any earthquake that occurs here is known as an intraplate earthquake.
The most widely accepted theory regarding the occurrence of intraplate earthquakes is that stress or pressure is released along ancient or hidden fault lines beneath the Earth’s crust, which might have formed during the breakup of Pangea. South Carolina has many fault lines. This pressure originates from the plates moving within the Earth’s mantle, a process that occurs over the course of millions of years and is known as the theory of plate tectonics.
Since intraplate earthquakes are far less common than interplate earthquakes, buildings far from plate boundaries are rarely made with earthquakes in mind; this increases the potential devastation that can happen as a result.
The 1886 Charleston Earthquake
In August 1886, an earthquake with a magnitude of 7.3 struck Charleston as the most damaging earthquake in the eastern United States. The impact of this earthquake was felt over 2.5 million square miles, from Cuba to New York. Many Charlestonians thought it was the end of the world, and were surprised that the majority of the devastation had occurred within our city. 60 people died as a result of this earthquake, and nearly every structure was severely damaged. When considering lives lost, human suffering, and devastation, it was the most destructive earthquake in the U.S. in the 19th century…