Waveform of today’s earthquake recorded on the first floor of the Research Building. Shown, bottom to top, are the vertical, north-south, and east-west components of ground velocity. Amplitudes are given in digital counts. Time is given on the horizontal axis and is in Coordinated Universal Time (UTC, 4 hours ahead of local time).

At 17:51:03 UTC, or 13:51:03 local time, an earthquake shook Carnegie’s Broad Branch Road campus.  According to the U.S. Geological Survey, the magnitude 5.9 earthquake originated in Virginia 141 km (88 miles) southwest of Washington, D.C., at 37.88°N, 77.95°W.

Field Seismologist Steven Golden provided the campus’s first waveform from data recorded inside DTM’s Research Building (see figure). Golden was conducting an instrument test in his office with a Streckeisen STS-2 seismometer connected to a REFTEK RT130 data logger. This waveform provides information on the response of the building to the ground movement.

“Even those of us who study earthquakes typically have experienced very few such events first hand,” says DTM Director Sean Solomon. “A few seconds after the first waves were felt, everyone was in the hallways comparing notes and watching the shaking.”

For Visiting Investigator Paul Rydelek, “this is scary only if you’ve never experienced a large earthquake.” Rydelek was in Japan during the magnitude 9 earthquake in March. “By comparison to what the citizens of Tokyo experienced, this would be considered a small aftershock,” he added.

Click here for more information on earthquakes in Virginia (courtesy Staff Scientist Diana Roman).

USGS Community Internet Intensity Map, Eastern Virginia (Courtesy: U.S. Geological Survey)