Earthquake · reviewed by a seismologist
M 2.1mb_lg
Earthquake near Alva, OK
No earthquake was likely felt in Alva in the 24 hours to 10:47 am CST (16:47 UTC). The last one was M 3.4, 144 km (90 mi) SSE, at 5:53 am CST on 7 November 2026, estimated intensity II (weak) in town; 23 felt reports to USGS. Every earthquake near Alva
This page: a magnitude 2.1 earthquake was recorded 32 km (20 mi) south-southeast of Alva, OK, at 12:13 pm CDT on 28 March 2016 (17:13 UTC), 6.1 km deep.
USGS: 11 km W of Aline, Oklahoma
- When
- 12:13 pm CDT on 28 March 2016 ()
- Where
- 32 km (20 mi) south-southeast of Alva, OK · earthquakes near Alva
- Oklahoma today
- every earthquake in Oklahoma in the last 24 hours
- Magnitude
- M 2.1 (mb_lg)
- Depth
- 6.1 km below the surface
- Felt
- no reports yet
- Nearest
- Major County, 24 km S
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 3806 days ago
Earthquake alerts for Alva, OK
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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 minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth, people at rest would likely notice it out to about 28 km (17 mi) from the epicentre. In Alva, 32 km away, the estimate is intensity II (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.
Likely felt in: Helena 28 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 43 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 350,000× the energy of this one
- Magna, Utah 2020 M 5.7 250,000× the energy of this one
- Around the size people start to feel M 3.0 22× the energy of this one
- This earthquake M 2.1 about 43 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
The largest earthquake within 50 km since 2016 was M 5.1 on 2016-02-13 — about 32,000 times the energy of this one.
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 36.5241, -98.5785. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Major County, OK | 24 km (15 mi) | S | earthquakes near Major County |
| Alfalfa County, OK | 32 km (20 mi) | NE | earthquakes near Alfalfa County |
| Woods County, OK | 34 km (21 mi) | NW | earthquakes near Woods County |
| Woodward County, OK | 63 km (39 mi) | W | earthquakes near Woodward County |
| Dewey County, OK | 72 km (45 mi) | SSW | earthquakes near Dewey County |
| Garfield County, OK | 72 km (45 mi) | ESE | earthquakes near Garfield County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
57 earthquakes have been recorded within 50 km since this one.
- 3.0 9 km NE of Quinlan, Oklahoma
- 2.7 8 km S of Byron, Oklahoma
- 2.8 9 km E of Avard, Oklahoma
- 2.3 17 km ESE of Waynoka, Oklahoma
- 2.2 18 km ESE of Waynoka, Oklahoma
- 3.3 18 km SW of Dacoma, Oklahoma
- 2.8 8 km NNE of Quinlan, Oklahoma
- 2.5 13 km SSE of Waynoka, Oklahoma
- 2.6 15 km SE of Waynoka, Oklahoma
- 2.6 9 km NNE of Quinlan, Oklahoma
- 3.1 16 km SE of Waynoka, Oklahoma
- 2.5 17 km SE of Waynoka, Oklahoma
- 2.6 5 km NNW of Ames, Oklahoma
- 2.5 17 km SW of Dacoma, Oklahoma
- 2.7 17 km SSE of Waynoka, Oklahoma
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.