M4.0 Earthquake near Alaska Peninsula — August 15, 2023
2023-08-15 18:09:36 UTC (2023-08-15) · approx. 7:09 AM UTC-11 local
On August 15, 2023 at 18:09 UTC, a magnitude 4.0 shallow crustal earthquake struck near Alaska Peninsula, at a depth of 35.0 km and coordinates 54.7777°, -161.2096°. The earthquake was reported felt by 1 personacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 1.2 (weak).
Physical scale: An earthquake of magnitude 4.0 releases seismic energy equivalent to roughly 15 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 347 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
-161.2096°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.0 earthquake near Alaska Peninsula?
The magnitude 4.0 earthquake that struck near Alaska Peninsula on August 15, 2023 at 18:09 UTC had a depth of 35.0 km. It was felt by 1 person with maximum shaking intensity of MMI 1.2 (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 4.0 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 4.0 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us7000knip). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, August 15, 2023). M4.0 Earthquake near Alaska Peninsula — August 15, 2023. Retrieved October 27, 2023 from https://www.earthquaketracker.org/earthquakes/event/us7000knip/