South Carolina’s lowcountry was hit by two 2.2-magnitude earthquakes on Friday, causing no damage.
According to the Greenville News, the epicenters of both earthquakes were detected around Summerville, which is located about three hours from Greenville and about 30 minutes from Charleston.
Per the details provided by the U.S. Geological Survey (USGS) report, the first earthquake struck around 8:06 a.m. on Friday with a depth of 5.9 kilometers. The epicenter of the first quake was about 2.6 miles southwest of Summerville.
The second earthquake was detected around 10:42 a.m. the same day, with a depth of 4.4 kilometers. Per the USGS report, the epicenter of the second tremor was about one mile northeast of Summerville, the Greenville News report said.
The two earthquakes’ measurement of 2.2. on the Richter scale is considered to be low in intensity and such earthquakes are called “micro” quakes. Per a report by the State, a micro quake is generally not felt by people, though recorded on local instruments. According to the USGS website, the recent quakes in Summerville were categorized as weak to light, which generally do not cause damage.
“Moderately damaging earthquakes strike the inland Carolinas every few decades, and smaller earthquakes are felt about once each year or two.”
With the latest two earthquakes, South Carolina has been hit by a total of eight earthquakes in 2018. The last one was detected in Bamburg County and had a magnitude of 2.6.
According to geologist Scott Howard, who talked to the State in May, “earthquakes tend to happen in bunches. Not that any one earthquake is the result of another earthquake but there just may be some local readjustments going on around the earthquake.”
The USGS report added that the most devastating earthquake that ever struck South Carolina was in 1886. The quake not only caused destruction, but is still considered one of the “largest historic shocks in Eastern North America,” as reported by the State. “It reached 7.3 magnitude and killed 60 people.”
USGS now confirming a second 2.2 magnitude #earthquake occurring yesterday near Summerville, S.C. That’s two 2.2s on 11/2 just more than two hours apart. More info: #sctweets #chsnews https://t.co/efDpzOfSZu pic.twitter.com/HroFKUzxnz— SCEMD (@SCEMD) November 3, 2018
Across the globe, several hundred magnitude 2.0 earthquakes occur every day, according to the Incorporated Research Institutions for Seismology. Thus, such micro quakes are quite common and unnoticeable, a separate report by the State said.
The somewhat unusual thing about the South Carolina earthquakes, however, is that the state is not situated near any major fault lines. And unlike the western United States, South Carolina is not located near the boundaries between tectonic plates in the earth’s outer layer either. According to geologist Howard, South Carolina experiences intraplate earthquakes.
“These are quakes that happen along faults, or cracks, within the earth’s plates. Earthquakes can also happen because of pressure buildup near water reservoirs or plutons, which are plugs of rock within the earth’s surface.”