Residents of southern California know that earthquakes can occur at any moment due to the region’s seismic activity. However, it may be surprising to learn that other areas of the United States, such as central Virginia and the Lowcountry of South Carolina, are also at risk for significant earthquakes in the future.
These unexpected seismic hotspots pose a greater threat as they often lack the preparedness seen in more seismically active regions. Charleston, South Carolina, for example, experienced a catastrophic earthquake in 1886, reaching a magnitude of 7.3 on the Richter scale, which resulted in 60 fatalities and an estimated $186 million in damages, a staggering figure when adjusted for inflation.
Recent advancements in the National Seismic Hazard Model have allowed scientists to better understand the likelihood of earthquakes in different locations, based on the underlying geological factors. This model assesses the types of earthquakes that might occur and evaluates the probability of seismic events based on known fault lines.
Researchers are also studying liquefaction, a process that occurs when the water-saturated ground loses its strength due to the shaking of an earthquake, making the ground more vulnerable to damage.
Mark Petersen, a research geophysicist with the U.S. Geological Survey, noted in a recent report that findings revealed around 75 percent of the U.S. possesses historical records of potentially damaging earthquakes. This indicates a significant risk of light damage across much of the country, which was unexpected.
The report utilized an extensive set of geological data, identifying 350 new fault lines, which could lead to future seismic activity. These findings highlight the potential vulnerabilities of various regions to earthquakes.
While the San Andreas Fault is often cited as a likely candidate for the next major earthquake, given its last significant event in 1857, places like Mineral, Virginia, have also experienced notable seismic activity. In August 2011, a 5.8 magnitude earthquake struck Mineral, felt by millions along the East Coast, causing over $200 million in damages, including to the Washington Monument.
Petersen emphasizes the need for increased awareness of earthquake risks, particularly in the eastern U.S., which may not be as familiar with seismic threats. Quakes in these regions can affect a much larger area compared to those in the West, leading to broader impacts when they occur.
The ongoing study of potential earthquake zones allows for modifications in building codes to enhance resilience against future quakes, although the precise timing and location of such events remain uncertain.