M4.2 Earthquake 14 km SW of Adak, Alaska — March 7, 2022
2022-03-07 21:40:52 UTC (2022-03-07) · approx. 9:40 AM UTC-12 local
On March 7, 2022 at 21:40 UTC, a magnitude 4.2 intermediate depth earthquake struck 14 km SW of Adak, Alaska, at a depth of 75.1 km and coordinates 51.7738°, -176.7690°. The earthquake was reported felt by 1 personacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 3.3 (light).
Physical scale: An earthquake of magnitude 4.2 releases seismic energy equivalent to roughly 30 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 476 m — a useful intuition for the size of the slip patch on the fault.
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 1 citizen response 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
-176.7690°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.2 earthquake near Adak, Alaska?
The magnitude 4.2 earthquake that struck 14 km SW of Adak, Alaska on March 7, 2022 at 21:40 UTC had a depth of 75.1 km. It was felt by 1 person with maximum shaking intensity of MMI 3.3 (light). For context, this was a light earthquake commonly felt near the epicenter.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.2 earthquakes can continue for several days and gradually diminish over time.
Actions
Understanding This Data
Magnitude 4.2 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us6000h2w3). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2022, March 7, 2022). M4.2 Earthquake 14 km SW of Adak, Alaska — March 7, 2022. Retrieved May 14, 2022 from https://www.earthquaketracker.org/earthquakes/event/us6000h2w3/