M3.6 Earthquake 7 km E of Nescatunga, Oklahoma — September 19, 2021
2021-09-19 22:24:34 UTC (2021-09-19) · approx. 3:24 PM UTC-7 local
Felt by 10 people across nearby locations. Maximum shaking intensity MMI 4.3 (moderate).
On September 19, 2021 at 22:24 UTC, a magnitude 3.6 shallow crustal earthquake struck 7 km E of Nescatunga, Oklahoma, at a depth of 7.8 km and coordinates 36.7578°, -98.0650°. The earthquake was reported felt by 10 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 4.3 (moderate). This earthquake was detected by 101 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 204, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 3.6 releases seismic energy equivalent to roughly 3.9 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 187 m — a useful intuition for the size of the slip patch on the fault.
The epicenter is located in Oklahoma, a region characterized by induced seismicity from high-volume wastewater injection into the Arbuckle Group formation, which reactivates ancient basement faults. View all earthquakes in Oklahoma.
Learn more: Magnitude scale · Aftershock sequences
ShakeMap — predicted shaking intensity
Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 10 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Earthquake Details
-98.0650°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 3.6 earthquake near Nescatunga, Oklahoma?
The magnitude 3.6 earthquake that struck 7 km E of Nescatunga, Oklahoma on September 19, 2021 at 22:24 UTC had a depth of 7.8 km. It was felt by 10 people with maximum shaking intensity of MMI 4.3 (moderate). For context, this was a minor earthquake typically detected only by instruments.
Where did the earthquake occur?
The earthquake epicenter was located at 36.7578°, -98.0650°, which is 7 km E of Nescatunga, Oklahoma. View all earthquakes in Oklahoma.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.6 earthquakes can continue for several days and gradually diminish over time.
Has Oklahoma had earthquakes this big before?
The largest recorded earthquake in Oklahoma was the M5.8 Pawnee earthquake of September 3, 2016. Today's magnitude 3.6 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: ok2021skor). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, September 19, 2021). M3.6 Earthquake 7 km E of Nescatunga, Oklahoma — September 19, 2021. Retrieved December 3, 2021 from https://www.earthquaketracker.org/earthquakes/event/ok2021skor/