An earthquake struck central Maryland a short time ago, nearly 24 hours after another earthquake hit south near Richmond, Virginia. The magnitude 2.0 event struck just outside of Sykesville, Maryland in Carroll County at 11:49 pm. The seismic event, which had a depth of 5 km, was felt by more than 125 people who used the “Did You Feel It?” took on the USGS earthquake website.
Maryland rarely experiences earthquakes but the volume has been increasing over time. According to USGS and the Maryland Emergency Management Agency, between 1758 and 1987 Maryland experienced 22 minor earthquakes. However, from January 1990 through December 1996, Maryland experienced 35 small tremors—1 in Harford County, 2 in Cecil County, 3 in Baltimore County, and 29 in Howard County. In only seven years, the number of known earthquakes in Maryland more than doubled.
The most recent significant event was on July 16, 2010, when a 3.6 magnitude earthquake occurred near Germantown. Ground shaking was felt as far away as Annapolis and Northern Virginia.
According to the Maryland Emergency Management Agency, based on available data, the overall earthquake risk to all jurisdictions, with the exception of Cecil County, is low to medium-low, relative to Maryland. Cecil County is ranked as medium primarily driven by population vulnerability, density and geographic extent. Frederick, Montgomery, Prince George’s, Charles, Calvert, Anne Arundel, Baltimore and Wicomico counties and Baltimore City are ranked medium-low based primarily on population density and population vulnerability.
According to USGS, tonight’s earthquake was the first earthquake to hit Maryland in over a year. The last was a weak magnitude 1.7 event which struck near Woodlawn.
Several earthquakes in adjacent states have been felt in Maryland but Marylanders are more likely to feel one of these out-of-state earthquakes than one within Maryland. Southwestern Virginia, central Virginia, and the Atlantic seaboard northward from Wilmington, Delaware have significantly more seismic activity than does Maryland. One out-of-state earthquake that was felt in much of Maryland occurred Easter Sunday, April 22, 1984. In fact, it was reported felt in eight states and the District of Columbia, over an area of approximately 19,000 square miles. Centered about 12 miles south of Lancaster, Pennsylvania, this earthquake was measured as a 4.1 magnitude seismic event. According to the Maryland Geological Survey, most notable effects in Maryland were in the northeastern part of the state. The Lancaster earthquake is likely related to Triassic-age structures in the area.