M4.1 Earthquake 68 km NNW of Aleneva, Alaska — February 11, 2021
2021-02-11 20:08:53 UTC (2021-02-11) · approx. 10:08 AM UTC-10 local
On February 11, 2021 at 20:08 UTC, a magnitude 4.1 intermediate depth earthquake struck 68 km NNW of Aleneva, Alaska, at a depth of 72.9 km and coordinates 58.5892°, -153.4888°. The earthquake was reported felt by 1 personacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 3.0 (weak). The nearest populated place is Kodiak (population 6,130).
Physical scale: An earthquake of magnitude 4.1 releases seismic energy equivalent to roughly 21 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 406 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
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 | 18 |
Earthquake Details
-153.4888°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.1 earthquake near Aleneva, Alaska?
The magnitude 4.1 earthquake that struck 68 km NNW of Aleneva, Alaska on February 11, 2021 at 20:08 UTC had a depth of 72.9 km. It was felt by 1 person with maximum shaking intensity of MMI 3.0 (weak). 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 4.1 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 4.1 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: ak0211xsj2lp). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, February 11, 2021). M4.1 Earthquake 68 km NNW of Aleneva, Alaska — February 11, 2021. Retrieved April 22, 2021 from https://www.earthquaketracker.org/earthquakes/event/ak0211xsj2lp/