4.4

M4.4 Earthquake 74 km E of Port Alsworth, AlaskaMay 27, 2023

2023-05-27 16:49:23 UTC (2023-05-27) · approx. 6:49 AM UTC-10 local

Felt by 16 people across nearby locations.

MagnitudeM4.4(ml)
Time16:49 UTC6:49 AM UTC-10
Depth136.3 kmintermediate depth
Coordinates60.281°, -152.973°
Felt by16DYFI responses· max MMI 2.9
Status✓ Reviewed by USGS· Tsunami evaluation
Tsunami Warning Issued

On May 27, 2023 at 16:49 UTC, a magnitude 4.4 intermediate depth earthquake struck 74 km E of Port Alsworth, Alaska, at a depth of 136.3 km and coordinates 60.2811°, -152.9733°. The earthquake was reported felt by 16 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 2.9 (weak).

Physical scale: An earthquake of magnitude 4.4 releases seismic energy equivalent to roughly 60 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 655 m — a useful intuition for the size of the slip patch on the fault.

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

Map showing earthquake epicenter at 60.28°, -152.97°

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.

USGS ShakeMap intensity contours for the M4.4 earthquake near 74 km E of Port Alsworth, Alaska

Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 16 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.

USGS DYFI community-reported intensity map for the M4.4 earthquake near 74 km E of Port Alsworth, Alaska

Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report

Earthquake Details

Magnitude
4.4 ml
Depth
136.3 km
intermediate depth
Location
60.2811°N
-152.9733°E
Felt Reports
16
DYFI responses
Intensity (MMI)
2.9
weak
Community Intensity
2.7
CDI from reports

Technical Information

Event ID
ak0236rdtjd6
Event Type
earthquake
Status
✓ Reviewed
Significance
302
RMS Residual
0.91 sec
Last Updated
2023-07-29 22:00:44 UTC

Common Questions

How strong was the magnitude 4.4 earthquake near Port Alsworth, Alaska?

The magnitude 4.4 earthquake that struck 74 km E of Port Alsworth, Alaska on May 27, 2023 at 16:49 UTC had a depth of 136.3 km. It was felt by 16 people with maximum shaking intensity of MMI 2.9 (weak). For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at 60.2811°, -152.9733°, which is 74 km E of Port Alsworth, Alaska. View all earthquakes in Alaska.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.4 earthquakes can continue for several days and gradually diminish over time.

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 4.4 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: ak0236rdtjd6). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, May 27, 2023). M4.4 Earthquake 74 km E of Port Alsworth, AlaskaMay 27, 2023. Retrieved July 29, 2023 from https://www.earthquaketracker.org/earthquakes/event/ak0236rdtjd6/