Earthquake · reviewed by a seismologist
M 1.8ml
Earthquake near Alva, OK
No earthquake was likely felt in Alva in the 24 hours to 10:12 am CST (16:12 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 1.8 earthquake was recorded 17 km (10 mi) northwest of Alva, OK, at 3:47 pm CDT on 27 September 2020 (20:47 UTC), 5.7 km deep.
USGS: 16 km NW of Alva, Oklahoma
- When
- 3:47 pm CDT on 27 September 2020 ()
- Where
- 17 km (10 mi) northwest of Alva, OK · earthquakes near Alva
- Oklahoma today
- every earthquake in Oklahoma in the last 24 hours
- Magnitude
- M 1.8 (ml)
- Depth
- 5.7 km below the surface
- Felt
- no reports yet
- Nearest
- Woods County, 20 km SSW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2234 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 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 18 km (11 mi) from the epicentre. In Alva, 17 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: Alva 17 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 17 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 870,000× the energy of this one
- Magna, Utah 2020 M 5.7 620,000× the energy of this one
- Around the size people start to feel M 3.0 55× the energy of this one
- This earthquake M 1.8 about 17 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 78,000 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 36.9022, -98.8087. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Woods County, OK | 20 km (12 mi) | SSW | earthquakes near Woods County |
| Barber County, KS | 37 km (23 mi) | NNE | earthquakes near Barber County |
| Alfalfa County, OK | 47 km (29 mi) | ESE | earthquakes near Alfalfa County |
| Comanche County, KS | 50 km (31 mi) | NW | earthquakes near Comanche County |
| Woodward County, OK | 67 km (42 mi) | SW | earthquakes near Woodward County |
| Major County, OK | 70 km (43 mi) | SSE | earthquakes near Major County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
59 earthquakes have been recorded within 50 km since this one.
- 1.7 10.2 km SSW of Quinlan, OK
- 1.9 9 km NNE of Quinlan, Oklahoma
- 1.8 10 km WSW of Waynoka, Oklahoma
- 1.5 6.1 km N of Cherokee, OK
- 1.8 16 km SE of Waynoka, Oklahoma
- 1.7 17 km SE of Waynoka, Oklahoma
- 1.7 17 km SE of Waynoka, Oklahoma
- 2.0 9 km NNE of Quinlan, Oklahoma
- 1.9 9 km NNE of Quinlan, Oklahoma
- 1.7 10 km NNE of Quinlan, Oklahoma
- 1.6 10 km NNE of Quinlan, Oklahoma
- 1.6 9 km NNE of Quinlan, Oklahoma
- 1.5 9 km NNE of Quinlan, Oklahoma
- 1.7 9 km NNE of Quinlan, Oklahoma
- 1.5 9 km NNE of Quinlan, 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.