Earthquake · reviewed by a seismologist
M 2.8md
Earthquake near Greenbrier, AR
No earthquake was likely felt in Greenbrier in the 24 hours to 2:28 am CST (08:28 UTC). The last one was M 2.1, 21 km (13 mi) E, at 5:55 am CDT on 28 September 2026, estimated intensity II (weak) in town; 1 felt report to USGS. Every earthquake near Greenbrier
This page: a magnitude 2.8 earthquake was recorded 4 km (3 mi) north-northwest of Greenbrier, AR, at 9:16 am CST on 23 January 2021 (15:16 UTC), 6.4 km deep. 56 people have reported feeling it to USGS.
USGS: 4 km NNW of Greenbrier, Arkansas
61 km (38 mi) N of Little Rock, AR · 22 km (14 mi) NNE of Conway, AR
- When
- 9:16 am CST on 23 January 2021 ()
- Where
- 4 km (3 mi) north-northwest of Greenbrier, AR · earthquakes near Greenbrier
- Magnitude
- M 2.8 (md)
- Depth
- 6.4 km below the surface
- Felt
- 56 reports · strongest reported intensity IV
- Nearest
- Faulkner County, 15 km SSE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1582 days ago
Earthquake alerts for Greenbrier, AR
Get a notification in this browser when USGS records an earthquake near Greenbrier, AR. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.
At this magnitude and depth, people at rest would likely notice it out to about 60 km (37 mi) from the epicentre. In Greenbrier, 4 km away, the estimate is intensity III (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.
Earthquakes near other towns within 30 km: Conway, Vilonia.
How big was it?
This earthquake released about 450 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 34,000× the energy of this one
- Magna, Utah 2020 M 5.7 24,000× the energy of this one
- Around the size people start to feel M 3.0 2.1× the energy of this one
- This earthquake M 2.8 about 450 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 35.2688, -92.4045. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Faulkner County, AR | 15 km (9 mi) | SSE | earthquakes near Faulkner County |
| Conway County, AR | 26 km (16 mi) | W | earthquakes near Conway County |
| Van Buren County, AR | 36 km (23 mi) | NNW | earthquakes near Van Buren County |
| Cleburne County, AR | 51 km (32 mi) | NE | earthquakes near Cleburne County |
| Pulaski County, AR | 56 km (35 mi) | S | earthquakes near Pulaski County |
| White County, AR | 59 km (37 mi) | E | earthquakes near White County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
25 earthquakes have been recorded within 50 km since this one.
- 2.1 3 km E of Enola, Arkansas
- 2.3 3 km NW of Mount Vernon, Arkansas
- 1.7 8 km SW of Heber Springs, Arkansas
- 2.3 3 km NE of Greenbrier, Arkansas
- 2.0 3 km SSE of Guy, Arkansas
- 2.4 11 km W of Clinton, Arkansas
- 1.8 2 km WNW of Enola, Arkansas
- 2.2 10 km WSW of Center Ridge, Arkansas
- 1.9 5 km W of Damascus, Arkansas
- 2.1 5 km NNE of Greenbrier, Arkansas
- 2.0 Arkansas
- 2.3 6 km ESE of Center Ridge, Arkansas
- 1.7 1 km ENE of Enola, Arkansas
- 1.6 3 km WNW of Greenbrier, Arkansas
- 1.8 9 km WSW of Center Ridge, Arkansas
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.