Earthquake swarms have shaken the state of South Carolina within the past week.
Although there were no immediate reports of casualties or infrastructural damage, a growing concern for a potential strong earthquake is looming in the Eastern Seaboard region of the United States.
Over recent months, there have been multiple instances of earthquake swarms in North America's neighboring regions.
Authorities on geological and seismic activities provided the movement of tectonic plates under the sub-continent to be behind the tremors.
However, other explanations are still possible.
South Carolina Earthquake
In the early morning on Monday, May 9, a large number of residents in South Carolina awakened to the trembling vibration of an earthquake, which was classified by seismic authorities as a 3.3 magnitude on the Richter scale, as cited by ABC News.
The epicenter of the quake was traced to the northeast of South Carolina's capital city of Columbia.
The US media outlet cites over 4,000 people contacted the United States Geological Survey (USGS) to report what they felt during the early week earthquake.
While the intensity of the quake is relatively low, the seismic event is still significant since earthquakes in South Carolina and even across the East coast are very uncommon.
Following the quake at 1:30 a.m. EDT (local time) on Monday, state residents took to social media and purportedly described the tremor felt like a heavy truck was moving nearby after the earth-shaking effect lasted for several seconds, according to the Associated Press.
Since December 2021, there have been dozens of reported low-magnitude earthquakes in the same area, notably near the town of Elgin, situated approximately 21 miles (34 kilometers) northeast of the state capital.
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North Carolina Earthquake
Meanwhile, in North Carolina, a low-intensity 2.2 magnitude earthquake was reportedly recorded near the town of Catawba in the early morning of Wednesday, May 11.
The quake struck before 12:45 a.m. with also no immediate reports of casualties or damage.
The quake comes days after South Carolina was rocked by seven earthquakes in total this week in less than 48 hours, including the mentioned 3.3 magnitudes.
Earthquake Swarms
Following the recent seismic activities, Dr. Scott White from the University of South Carolina called the tremors in the Carolinas earthquake swarms, but it still has not provided any answer on the numerous quakes, as cited by Fox Carolina.
The presumption comes from the fact that South Carolina only receives an annual average of 20 earthquakes.
Since the start of 2022, more than 30 small earthquakes have been reported already.
Due to the intensity and frequency of the earthquakes during the said period, earthquake swarms have emerged as potential geological candidates from recent events.
Characterized as short-lived earthquakes without a main identifiable shock or a very large mainshock, the USGS said earthquake swarms can continuously occur or recur for days, weeks, months, or even years.
There are no known tectonic plate boundaries under the East Coast of the Continental US.
The region is only part of the North American plate, where "major" earthquakes rarely occur.
Unlike the said tectonic plate, earthquakes are frequent in the Pacific Ring of Fire, a horseshoe-shaped region across the Pacific Ocean where volcanic eruptions and earthquakes are common.
In the US, the western coast is within this seismically-active region.
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