At around a quarter of noon on February 26, social media was abuzz with discussions about the earthquake that had just struck the Colombian region. Many people said their homes were shaken by the quake, with some reporting hearing rumbling sounds and others sharing videos of furniture swinging from home security cameras.
this Magnitude 3 earthquake It was small and harmless — a common occurrence in South Carolina — but it was the strongest hurricane to hit the central region. more than ten yearsU.S. Geological Survey records show.
This is also the case more than five times east shore of lake murray An analysis of the past quarter-century of U.S. Geological Survey data found that the quakes occurred in less than three weeks, reflecting a surge in earthquakes in the central region since 2021.
Data shows that in the five years since March 2021, central region Experienced 19 earthquakes of at least magnitude 2.5 (the threshold at which seismometers can detect all earthquakes and year-to-year comparisons are reliable).
By comparison, only six such earthquakes occurred in the central region between 2000 and 2020, with 19 in the lowlands and 15 in the north.
Most of the recent earthquakes in the central region have been “Swarm” between Elgin and Lugoffa series of small earthquakes in a closed location, but no major earthquakes.
Scientists now say the same phenomenon occurs in the Lake Murray region, but its explanation remains elusive.
“It looks like there’s a small group there,” said Thomas Pratt, a U.S. Geological Survey research geophysicist and federal bureau coordinator. Earthquake Disaster Plan in the central and eastern states.
“Why we have earthquakes in the middle of this stability boundary is a bit of a mystery,” he said, referring to the lack of major fault lines in the eastern United States. “We can’t predict whether it will continue, die out or cause larger problems.”
Certain industrial activities – such as fracking and water injection – can trigger earthquakes because they generate water pressure that can lubricate the Earth’s tectonic faults and push them apart, Platt said. The reduced friction allows the faults to slide, releasing energy that travels through the crust, cause vibration.
The release of energy also creates accompanying noise, said Scott Howard, a geologist with the South Carolina Department of Natural Resources.
“This transition from rock to air is like a booming sound,” Howard said. Some describe it as a rumbling noise, similar to a moving train or large truck.
Researchers from the University of South Carolina, the College of Charleston and the Georgia Institute of Technology are studying the Elgin-Lugoff group to try to understand why.
Geologists are explore Whether the group has some connection to the nearby Waterley River, such as changes in water levels and rainfall in the area.
Platt doesn’t believe human activity caused the recent earthquakes in the Columbia area. he censored water level changes Murray Lake reservoirs and thought they were too small to cause earthquakes.
“Why don’t earthquakes occur during early water level changes?” he said.
No one can predict where and when an earthquake will occur, or how strong it will be. But geologists say large-scale occurrences are rare in South Carolina. The strongest earthquake ever recorded in the state and along the East Coast was a magnitude 7.6 earthquake. Raid on Charleston 1886 and killed about 60 people.
Experts say small earthquakes should remind residents to pay attention to earthquake prevention emergency plan And supplies are in place. That includes figuring out in advance how to communicate with your family in the event of a major natural disaster.
If there is a strong earthquake and objects or building materials start falling, look for cover under a table or table and grab onto it. try stay indoorsstay away from dangerous areas such as windows and kitchens.
People should not run outdoors because they may trip, bump into things, or be hit by debris.
“It’s falling objects that kill people,” Platt said. “Earthquakes don’t kill people.”
