Earthquake · reviewed by a seismologist
M 2.5ml
Earthquake near Alva, OK
No earthquake was likely felt in Alva in the 24 hours to 10:10 am CST (16:10 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 2.5 earthquake was recorded 25 km (16 mi) southeast of Alva, OK, at 8:13 am CST on 21 December 2016 (14:13 UTC), 2.1 km deep. 1 person has reported feeling it to USGS.
USGS: 6 km NNW of Carmen, Oklahoma
- When
- 8:13 am CST on 21 December 2016 ()
- Where
- 25 km (16 mi) southeast of Alva, OK · earthquakes near Alva
- Oklahoma today
- every earthquake in Oklahoma in the last 24 hours
- Magnitude
- M 2.5 (ml)
- Depth
- 2.1 km below the surface
- Felt
- 1 report · strongest reported intensity II
- Nearest
- Alfalfa County, 18 km NE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 3528 days ago
Earthquake alerts for Alva, OK
Get a notification in this browser when USGS records an earthquake near Alva, OK. 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 46 km (29 mi) from the epicentre. In Alva, 25 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: Cherokee 18 km, intensity III · Helena 21 km, intensity II · Alva 25 km, intensity II · Fairview 40 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 170 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 89,000× the energy of this one
- Magna, Utah 2020 M 5.7 63,000× the energy of this one
- Around the size people start to feel M 3.0 5.6× the energy of this one
- This earthquake M 2.5 about 170 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 7,900 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 36.6317, -98.4859. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Alfalfa County, OK | 18 km (11 mi) | NE | earthquakes near Alfalfa County |
| Woods County, OK | 35 km (22 mi) | WNW | earthquakes near Woods County |
| Major County, OK | 36 km (22 mi) | S | earthquakes near Major County |
| Grant County, OK | 65 km (40 mi) | ENE | earthquakes near Grant County |
| Barber County, KS | 68 km (42 mi) | NNW | earthquakes near Barber County |
| Garfield County, OK | 68 km (42 mi) | ESE | earthquakes near Garfield County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
48 earthquakes have been recorded within 50 km since this one.
- 3.0 9 km WSW of Waynoka, Oklahoma
- 2.8 13 km SSW of Wakita, Oklahoma
- 2.6 10 km SW of Waynoka, Oklahoma
- 2.5 9 km SW of Waynoka, Oklahoma
- 2.5 3 km NNW of Fairview, Oklahoma
- 3.0 1 km NNW of Lambert, Oklahoma
- 2.5 17 km SSE of Waynoka, Oklahoma
- 2.5 9 km WSW of Waynoka, Oklahoma
- 2.8 6 km S of Lahoma, Oklahoma
- 2.6 1 km N of Lambert, Oklahoma
- 3.1 Oklahoma
- 2.5 9 km SW of Waynoka, Oklahoma
- 3.3 Oklahoma
- 2.5 7 km SE of Byron, Oklahoma
- 2.6 12 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.