M4.5 Earthquake 70 km SE of False Pass, Alaska — August 27, 2024
2024-08-27 22:12:01 UTC (2024-08-27) · approx. 11:12 AM UTC-11 local
Felt by 6 people across nearby locations. Aftershock of the M5.4 mainshock.
On August 27, 2024 at 22:12 UTC, a magnitude 4.5 shallow crustal earthquake struck 70 km SE of False Pass, Alaska, at a depth of 61.8 km and coordinates 54.3454°, -162.7597°. The earthquake was reported felt by 6 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 3.5 (light). This earthquake was detected by 164 seismic stations with good location accuracy and was assigned a USGS significance rating of 313, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.5 releases seismic energy equivalent to roughly 85 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 767 m — a useful intuition for the size of the slip patch on the fault.
This earthquake is part of an ongoing aftershock sequence following the magnitude 5.4 mainshock that occurred 26 days ago 93 km SE of False Pass, Alaska. Since the mainshock, the USGS has recorded 20 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
The epicenter is located in Alaska, a region characterized by Pacific Plate subduction beneath the North American Plate, producing frequent megathrust and crustal earthquakes along the Aleutian arc. The nearest mapped fault system is the Aleutian megathrust. View all earthquakes in Alaska.
Learn more: Magnitude scale · Aftershock sequences
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 6 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
Earthquake Details
-162.7597°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.5 earthquake near False Pass, Alaska?
The magnitude 4.5 earthquake that struck 70 km SE of False Pass, Alaska on August 27, 2024 at 22:12 UTC had a depth of 61.8 km. It was felt by 6 people with maximum shaking intensity of MMI 3.5 (light). For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 54.3454°, -162.7597°, which is 70 km SE of False Pass, Alaska. View all earthquakes in Alaska.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.5 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.4 one earlier?
No. This magnitude 4.5 earthquake is an aftershock of the larger magnitude 5.4 mainshock that occurred earlier 93 km SE of False Pass, Alaska. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
Has Alaska had earthquakes this big before?
The largest recorded earthquake in Alaska was the M9.2 Great Alaska earthquake of March 27, 1964. Today's magnitude 4.5 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us6000nn4i). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2024, August 27, 2024). M4.5 Earthquake 70 km SE of False Pass, Alaska — August 27, 2024. Retrieved November 9, 2024 from https://www.earthquaketracker.org/earthquakes/event/us6000nn4i/