Special Event: Edgefield, South Carolina

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February 15, 2014 M4.1 earthquake in Edgefield, South Carolina

Event parameters (from USGS)

Please check the USGS page for the latest official information.

Magnitude 4.1
UTC Time Saturday, February 15, 2013 at 03:23:38 UTC
Local Time Friday, February 14, 2013 at 22:23:38 at epicenter
Location 33.812°N, 82.063°W
Depth 4.8km (3 miles)
Region WNW of Edgefield, South Carolina
Distances 12km (7mi) WNW of Edgefield, South Carolina
31km (19mi) NNE of Evans, Georgia
32km (20mi) N of Martinez, Georgia
35km (22mi) NNW of North Augusta, South Carolina
97km (60mi) WSW of Columbia, South Carolina

Links

USGS event summary page

USGS regional moment tensor

USGS did you feel it

Map of eastern US earthquakes

Array Network Facility special event page


Peak displacements following two M4.1 earthquakes
Figure 1: Peak vertical displacements recorded following two M4.1 earthquakes. Note that the color scale is nonlinear and the values are very small. Also, radiation pattern hasn’t been taken into account since a focal mechanism for the CA event wasn’t found when making this figure. If someone has done a mechanism for this event, please post a link to it in the comments below or suggest an event with a similar mechanism if you know of one. Note: this figure was updated and now plots station symbols in descending order, which better shows the largest displacements near the epicenter of the CA event where many symbols overlap. (IRIS DMC)

Video 1: The seismic data is recorded at a USArray station Y55A about 23 km away from the epicenter. The data is played at 50 times the normal speed, and the amplitude is 50 times louder. The loudest noise is from the mainshock, and two pops are likely aftershocks. (Zhigang Peng, Georgia Tech)

BHZ record section using select TA data from 0 to 7 degrees
Figure 2: BHZ record section using select TA data from 0 to 7 degrees. (IRIS DMC)

Amplitude normalized BHZ record section using select TA data from 0 to 7 degrees
Figure 3: Amplitude normalized BHZ record section using select TA data from 0 to 7 degrees. (IRIS DMC)

Log plot
Figure 4: Log-amplitude plot for the nearest USArray station: Y55A. Two or three aftershocks can be seen following the main arrival. The signal just before the main arrival is likely local noise and not a foreshock, since it has little energy below 8Hz (see spectragram in Video 1). (Zhigang Peng, Georgia Tech)

Record Section of all available data from 0 to 10 degrees.
Figure 5: Record section of all available data from 0 to 10 degrees. (IRIS DMC)

Record Section of all TA data from 0 to 10 degrees
Figure 6: Record section of all TA data from 0 to 10 degrees. (IRIS DMC)

Record Section of CEUSN data from 0 to 10 degrees
Figure 7: Record section of CEUSN data from 0 to 10 degrees. (IRIS DMC)

Record Section of all available data from 0 to 10 degrees minus TA & N4 data
Figure 8: Record section of all available data from 0 to 10 degrees minus TA & N4 data (same as FIgure 9). (IRIS DMC)

Record Section of all available data from 0 to 10 degrees minus CEUSN data
FIgure 9: Record section of all available data from 0 to 10 degrees minus CEUSN data (same as Figure 8). (IRIS DMC)

Record section from the South Carolina Seismic Network
Figure 10: Record section from the South Carolina Seismic Network. Note that the y-axis spacing is regular and not according to distance. (Thomas Owens USC)

The IRIS DMC event page for this event contains links to additional tools and data.

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