Earthquake · reviewed by a seismologist
M 1.6md
Earthquake near Union, SC
USGS: 7 km ENE of Cross Anchor, South Carolina
57 km (35 mi) ESE of Greenville, SC · 106 km (66 mi) SW of Charlotte, NC
- When
- 2:40 am EDT on 4 April 2023 ()
- Where
- 16 km (10 mi) WSW of Union, SC · earthquakes near Union
- Magnitude
- M 1.6 (md)
- Depth
- 11 km below the surface
- Felt
- 2 reports · strongest reported intensity III
- Nearest
- Union County, 15 km ENE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1277 days ago
A magnitude 1.6 earthquake was recorded 16 km (10 mi) WSW of Union, SC, at 2:40 am EDT on 4 April 2023 (06:40 UTC). 2 people have reported feeling it to USGS. This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
Earthquakes near other towns within 30 km: Buffalo, Monarch Mill, Clinton, Whitmire, Watts Mills, Woodruff.
How big was it?
This earthquake released about 8.1 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,900,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,300,000× the energy of this one
- Around the size people start to feel M 3.0 120× the energy of this one
- This earthquake M 1.6 about 8.1 lb of TNT
Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.
For this area
No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.
Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.
Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.
Where
Epicentre 34.6605, -81.7807. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Union County, SC | 15 km (10 mi) | ENE | earthquakes near Union County |
| Laurens County, SC | 28 km (18 mi) | SW | earthquakes near Laurens County |
| Spartanburg County, SC | 36 km (22 mi) | NNW | earthquakes near Spartanburg County |
| Newberry County, SC | 44 km (28 mi) | SSE | earthquakes near Newberry County |
| Cherokee County, SC | 46 km (29 mi) | NNE | earthquakes near Cherokee County |
| Chester County, SC | 57 km (35 mi) | E | earthquakes near Chester County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
5 earthquakes have been recorded within 50 km since this one.
- 2.1 9 km E of Cross Anchor, South Carolina
- 1.9 9 km E of Cross Anchor, South Carolina
- 1.8 8 km E of Cross Anchor, South Carolina
- 2.0 6 km NNW of Coronaca, South Carolina
- 1.9 5 km NNW of Coronaca, South Carolina
Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.
On USGS
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.