august 9, 2020 sparta, n.c. (mw 5.1)
TRANSCRIPT
“P” and “S” mark P- and S-wave arrival times, re-spectively, at monitoring station EK32 in Jackson, Ky. Peak surface-wave displacement recorded at HZKY (Hazard, Ky.) is labeled. Some differences in waveform appearances are due to the different types of KSSMN instruments.
(~200-750 km away)
P S Surface Waves
FMKY
ROKY
SOKY
FLKY
SMKY
CUSSO
LOKY
BHKY
MOKY
PKKY
PAKYHZKY
14
26
21
32
2322
25
35A
Map LegendWeak Motion Station
(velocity sensor)
Strong Motion Station(acceleration sensor)
Weak & Strong Motion Station(velocity & acceleration sensors)
Vertical Seismic Array(multiple down-hole sensors)
Temporary weak-motion station
84˚W 82˚W 80˚W 78˚W
34˚N 34˚N
36˚N 36˚N
38˚N 38˚N
VIRGINIA-NORTH CAROLINA BORDER REGIONUSGS Community Internet Intensity Map
2020-08-09 12:07:37 UTC 36.4755N 81.0935W M5.1 Depth: 7 km ID:se60324281
Processed: Wed Aug 12 13:00:18 2020 vmdyfi1
Charlotte
Atlanta
Raleigh
Cincinnati
Lexington
Greensboro
Augusta-Richmond
Richmond
Arling
Knoxville
ColumbiaWilmington
Roanoke
Roswell
GreenvilleAsheville
Jacksonvill
GermantoHamilton
Rock Hill
Johnson City
104086 responses, 90785 plotted in 3263 ZIP codes and 19 cities (Max CDI = VI)
CITY SIZE
2M+
100,000+10,000+<10,000
84˚W 82˚W 80˚W 78˚W
34˚N 34˚N
36˚N 36˚N
38˚N 38˚N
100 miles
INTENSITY
DAMAGE
SHAKING
I II-III IV V VI VII VIII IX X+
none none none Very light Light Moderate Moderate/Heavy Heavy Very Heavy
Not felt Weak Light Moderate Strong Very strong Severe Violent Extreme
LegendDikes, sills, veinsFoldsFaults
Seismicity since 1900Earthquakes
M ≥ 5 (before 1900)Foreshocks and Aftershocks
(http://earthquake.usgs.gov/earthquakes/eventpage/se60324281)
KSSMN Seismic StationsStations with seismograms are labeled by name.
KSSMN Seismograms0.5 mm
(Hazard, Ky.)
USGS Source Mechanism
This focal mechanism, derived from seismograms, shows that oblique-re-verse faulting occurred on a west- or northeast-dipping fault plane.
The August 9, 2020 moment magnitude 5.1 earthquake near Sparta, North Carolina, occurred in a region of sparse and infrequent earthquake activity (below). The earthquake is the largest event within 100 km of the epicenter to have occurred since 1897 and was felt across a large area (below, left), and caused damage near the epicenter. As with most earthquakes in the central and eastern U.S., this event did not occur on a known fault. The source mechanism (below, right) indicates that compressive tectonic forces caused rupture on an upper-crustal fault whose orientation is oblique to the major structures related to the Appalachian mountains, which trend northeast-southwest in the region.
(http://earthquake.usgs.gov/earthquakes/eventpage/se60324281)
August 9, 2020 Sparta, N.C. (Mw 5.1)12:07:37 UTC / 08:07:37 at epicenter
University of Kentucky Kentucky Seismic and Strong Motion Network