M4.4 Earthquake 45 km ESE of Littlefield, Arizona — September 19, 2022
2022-09-19 21:18:14 UTC (2022-09-19) · approx. 1:18 PM UTC-8 local
Felt by 514 people across surrounding communities. Maximum shaking intensity MMI 4.6 (moderate).
On September 19, 2022 at 21:18 UTC, a magnitude 4.4 shallow crustal earthquake struck 45 km ESE of Littlefield, Arizona, at a depth of 10.0 km and coordinates 36.6773°, -113.4980°. The earthquake was reported felt by 514 peopleacross surrounding communities, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 4.6 (moderate). The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. This earthquake was detected by 62 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 473, placing it among routine seismic activity. The nearest populated place is Hurricane (population 13,748).
Physical scale: An earthquake of magnitude 4.4 releases seismic energy equivalent to roughly 60 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 655 m — a useful intuition for the size of the slip patch on the fault.
Nearest Populated Places
What the Shaking Felt Like
At MMI 4.6 (moderate), people in the most strongly affected areas would have experienced: Mild shaking, similar to a passing truck. Hanging objects swing. Glasses and dishes may rattle. Not commonly felt outdoors.
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 514 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
Population exposure (USGS PAGER)
Estimated population that experienced each level of shaking. Based on the USGS PAGER rapid impact assessment, which combines ShakeMap output with global population grids.
| Shaking intensity (MMI) | Description | Population exposed |
|---|---|---|
| MMI 3 | weak | 158,512 |
| MMI 4 | light | 84 |
Earthquake Details
-113.4980°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.4 earthquake near Littlefield, Arizona?
The magnitude 4.4 earthquake that struck 45 km ESE of Littlefield, Arizona on September 19, 2022 at 21:18 UTC had a depth of 10.0 km. It was felt by 514 people with maximum shaking intensity of MMI 4.6 (moderate). For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 36.6773°, -113.4980°, which is 45 km ESE of Littlefield, Arizona. The nearest populated place is Hurricane (population 13,748).
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.4 earthquakes can continue for several days and gradually diminish over time.
Authoritative source: USGS event page (event ID: us7000i9d9). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2022, September 19, 2022). M4.4 Earthquake 45 km ESE of Littlefield, Arizona — September 19, 2022. Retrieved December 21, 2022 from https://www.earthquaketracker.org/earthquakes/event/us7000i9d9/