The August 9, 2020 earthquake
M5.1near Sparta, North Carolina
A magnitude 5.1 earthquake 2.6 miles deep, centred in Alleghany County. The 2nd strongest in North Carolina’s record since 1900, and the strongest within 50 miles in the catalogue, which runs from 1900. 1 aftershock of magnitude 2.5 or more followed within 30 days.
The earthquake
- Magnitude
- 5.1
- moment magnitude (mw)
- Depth
- 2.6 mi
- 4.1 km below the surface
- Local time
- Sunday, August 9, 2020
- 08:07 EDT; 12:07 UTC
- In North Carolina’s record
- 2nd
- strongest of 79 since 1900
USGS ANSS Comprehensive Earthquake Catalog, event se60324281 (“4 km SE of Sparta, North Carolina”). The USGS event page carries the ShakeMap, felt reports and the official summary.
Aftershocks
Earthquakes of magnitude 2.5 or more within 20 miles of the epicentre in the 30 days after.
1
Aftershocks in 30 days
2.9
Largest aftershock, Aug 11, 2020
0
On the first day
1
In the 7 days before
- The search radius is the surface rupture length expected for an earthquake of this magnitude (Wells and Coppersmith, 1994), at least 20 and at most 600 miles, so a great earthquake's sequence is counted along its whole fault.
Counties and cities within 50 miles
Distance from the epicentre to each county boundary (zero when inside) and to each city centre.
Counties, nearest 30 of 31
- Alleghany CountyNC · inside
- Wilkes CountyNC · 2.4 mi
- Surry CountyNC · 6.4 mi
- Ashe CountyNC · 10.5 mi
- Grayson CountyVA · 13.5 mi
- Galax cityVA · 13.7 mi
- Carroll CountyVA · 15.0 mi
- Yadkin CountyNC · 20.3 mi
- Wythe CountyVA · 20.3 mi
- Smyth CountyVA · 22.2 mi
- Patrick CountyVA · 27.0 mi
- Watauga CountyNC · 27.1 mi
- Iredell CountyNC · 29.4 mi
- Alexander CountyNC · 29.8 mi
- Washington CountyVA · 30.8 mi
- Johnson CountyTN · 32.5 mi
- Caldwell CountyNC · 33.1 mi
- Pulaski CountyVA · 33.9 mi
- Stokes CountyNC · 36.3 mi
- Davie CountyNC · 36.5 mi
- Bland CountyVA · 36.8 mi
- Floyd CountyVA · 38.1 mi
- Forsyth CountyNC · 38.2 mi
- Tazewell CountyVA · 41.6 mi
- Sullivan CountyTN · 42.2 mi
- Catawba CountyNC · 44.7 mi
- Avery CountyNC · 45.8 mi
- Montgomery CountyVA · 46.3 mi
- Rowan CountyNC · 47.6 mi
- Carter CountyTN · 48.0 mi
Cities, largest first
- StatesvilleNC · 49.2 mi
- ClemmonsNC · 49.5 mi
- BooneNC · 36.9 mi
- LenoirNC · 46.2 mi
- LewisvilleNC · 44.8 mi
- Mount AiryNC · 26.3 mi
Earthquakes around the epicentre
6 earthquakes of magnitude 3 or more within 50 miles of this epicentre since 1973.
No earlier earthquake of magnitude 5 or more within 50 miles in the catalogue since 1900.
USGS ANSS Comprehensive Earthquake Catalog. Local time is the time zone of the county nearest the epicentre. Magnitudes are as the catalogue reports them.