quarry blast · reviewed by a seismologist
M 1.6ml
Earthquake near Stillwater, OK
No earthquake was likely felt in Stillwater in the 24 hours to 3:46 pm CST (21:46 UTC). The last one was M 3.4, 105 km (65 mi) WSW, at 5:53 am CST on 7 November 2026, estimated intensity II (weak) in town; 23 felt reports to USGS. Every earthquake near Stillwater
No: USGS classifies this as a quarry blast, not an earthquake. A magnitude 1.6 quarry blast was recorded 46 km (29 mi) north-northeast of Stillwater, OK, at 12:27 pm CDT on 20 July 2023 (17:27 UTC), less than 1 km deep.
USGS: 6 km SW of Ralston, Oklahoma
45 km (28 mi) NE of Stillwater, OK · 129 km (80 mi) NNE of Oklahoma City, OK
- When
- 12:27 pm CDT on 20 July 2023 ()
- Where
- 46 km (29 mi) north-northeast of Stillwater, OK · earthquakes near Stillwater
- Oklahoma today
- every earthquake in Oklahoma in the last 24 hours
- Magnitude
- M 1.6 (ml)
- Depth
- 0.0 km below the surface
- Felt
- no reports yet
- Nearest
- Pawnee County, 19 km SSE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1210 days ago
Earthquake alerts for Stillwater, OK
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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 4 km (2 mi) from the epicentre. In Stillwater, 46 km away, the estimate is intensity I (not felt). 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: Fairfax, Pawnee.
USGS catalogues this as quarry blast, not an earthquake.
How big was it?
This earthquake released about 6.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 2,400,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,700,000× the energy of this one
- Around the size people start to feel M 3.0 150× the energy of this one
- This earthquake M 1.6 about 6.4 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 5.8 on 2016-09-03 — about 2,400,000 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 36.4698, -96.7895. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Pawnee County, OK | 19 km (12 mi) | SSE | earthquakes near Pawnee County |
| Osage County, OK | 38 km (24 mi) | ENE | earthquakes near Osage County |
| Noble County, OK | 41 km (26 mi) | WSW | earthquakes near Noble County |
| Payne County, OK | 47 km (29 mi) | SSW | earthquakes near Payne County |
| Kay County, OK | 50 km (31 mi) | NW | earthquakes near Kay County |
| Creek County, OK | 73 km (45 mi) | SSE | earthquakes near Creek County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
39 earthquakes have been recorded within 50 km since this one.
- 2.1 12 km NW of Pawnee, Oklahoma
- 1.9 4 km NW of Red Rock, Oklahoma
- 1.5 7 km SE of Perry, Oklahoma
- 1.6 7 km SE of Perry, Oklahoma
- 1.9 13 km NW of Pawnee, Oklahoma
- 1.7 13 km NW of Pawnee, Oklahoma
- 2.8 11 km NW of Morrison, Oklahoma
- 2.0 5 km W of Ponca City, Oklahoma
- 2.1 4 km W of Ponca City, Oklahoma
- 1.7 13 km NW of Pawnee, Oklahoma
- 2.0 5 km W of Ponca City, Oklahoma
- 1.6 5 km W of Ponca City, Oklahoma
- 1.7 5 km W of Ponca City, Oklahoma
- 1.7 5 km W of Ponca City, Oklahoma
- 3.0 11 km E of Red Rock, 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.