quarry blast · reviewed by a seismologist
M 1.9ml
Earthquake near Ponca City, OK
No earthquake was likely felt in Ponca City in the 24 hours to 7:03 am CST (13:03 UTC). The last one was M 3.4, 149 km (93 mi) SW, at 5:53 am CST on 7 November 2026, estimated intensity II (weak) in town; 23 felt reports to USGS. Every earthquake near Ponca City
No: USGS classifies this as a quarry blast, not an earthquake. A magnitude 1.9 quarry blast was recorded 31 km (19 mi) east of Ponca City, OK, at 11:15 am CDT on 19 August 2021 (16:15 UTC), less than 1 km deep.
USGS: 2 km SSW of Burbank, Oklahoma
96 km (60 mi) NW of Tulsa, OK
- When
- 11:15 am CDT on 19 August 2021 ()
- Where
- 31 km (19 mi) east of Ponca City, OK · earthquakes near Ponca City
- Oklahoma today
- every earthquake in Oklahoma in the last 24 hours
- Magnitude
- M 1.9 (ml)
- Depth
- 0.0 km below the surface
- Felt
- no reports yet
- Nearest
- Osage County, 30 km E
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1909 days ago
Earthquake alerts for Ponca City, 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 21 km (13 mi) from the epicentre. In Ponca City, 31 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.
Earthquakes near other towns within 30 km: Fairfax, McCord.
USGS catalogues this as quarry blast, not an earthquake.
How big was it?
This earthquake released about 21 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 710,000× the energy of this one
- Magna, Utah 2020 M 5.7 500,000× the energy of this one
- Around the size people start to feel M 3.0 45× the energy of this one
- This earthquake M 1.9 about 21 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 710,000 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 36.6752, -96.7382. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Osage County, OK | 30 km (19 mi) | E | earthquakes near Osage County |
| Kay County, OK | 39 km (24 mi) | WNW | earthquakes near Kay County |
| Pawnee County, OK | 40 km (25 mi) | S | earthquakes near Pawnee County |
| Noble County, OK | 55 km (34 mi) | SW | earthquakes near Noble County |
| Cowley County, KS | 63 km (39 mi) | N | earthquakes near Cowley County |
| Chautauqua County, KS | 69 km (43 mi) | NE | earthquakes near Chautauqua County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
53 earthquakes have been recorded within 50 km since this one.
- 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
- 2.0 5 km W of Ponca City, Oklahoma
- 2.0 4 km W of Ponca City, Oklahoma
- 2.2 12 km NW of Pawnee, Oklahoma
- 1.6 11 km E of Red Rock, Oklahoma
- 2.6 8 km N of Morrison, Oklahoma
- 1.7 4 km ESE of Skedee, Oklahoma
- 1.9 9 km NNW of Pawnee, Oklahoma
- 3.0 9 km NNW of Pawnee, Oklahoma
- 2.4 3 km NE of Marland, 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.