“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