M3.5 Earthquake 32 km WNW of Kalifornsky, Alaska — July 21, 2023
2023-07-21 21:09:05 UTC (2023-07-21) · approx. 11:09 AM UTC-10 local
On July 21, 2023 at 21:09 UTC, a magnitude 3.5 intermediate depth earthquake struck 32 km WNW of Kalifornsky, Alaska, at a depth of 77.9 km and coordinates 60.4913°, -151.8675°.
Physical scale: An earthquake of magnitude 3.5 releases seismic energy equivalent to roughly 2.7 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 157 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
Earthquake Details
-151.8675°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 3.5 earthquake near Kalifornsky, Alaska?
The magnitude 3.5 earthquake that struck 32 km WNW of Kalifornsky, Alaska on July 21, 2023 at 21:09 UTC had a depth of 77.9 km. For context, this was a minor earthquake typically detected only by instruments.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.5 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 3.5 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: ak0239af45c3). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, July 21, 2023). M3.5 Earthquake 32 km WNW of Kalifornsky, Alaska — July 21, 2023. Retrieved September 28, 2023 from https://www.earthquaketracker.org/earthquakes/event/ak0239af45c3/