3.5

M3.5 Earthquake 45 km ESE of Ugashik, AlaskaMay 19, 2025

2025-05-19 23:43:45 UTC (2025-05-19) · approx. 1:43 PM UTC-10 local

MagnitudeM3.5(ml)
Time23:43 UTC1:43 PM UTC-10
Depth106.1 kmintermediate depth
Coordinates57.327°, -156.719°
Felt by2DYFI responses· max MMI 3.2
Status✓ Reviewed by USGS

On May 19, 2025 at 23:43 UTC, a magnitude 3.5 intermediate depth earthquake struck 45 km ESE of Ugashik, Alaska, at a depth of 106.1 km and coordinates 57.3268°, -156.7187°. The earthquake was reported felt by 2 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 3.2 (light).

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.

Map showing earthquake epicenter at 57.33°, -156.72°

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 M3.5 earthquake near 45 km ESE of Ugashik, Alaska

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

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 2 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 M3.5 earthquake near 45 km ESE of Ugashik, Alaska

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

Earthquake Details

Magnitude
3.5 ml
Depth
106.1 km
intermediate depth
Location
57.3268°N
-156.7187°E
Felt Reports
2
DYFI responses
Intensity (MMI)
3.2
light
Community Intensity
2.7
CDI from reports

Technical Information

Event ID
ak0256e9nisx
Event Type
earthquake
Status
✓ Reviewed
Significance
189
RMS Residual
0.67 sec
Last Updated
2025-07-25 17:06:20 UTC

Common Questions

How strong was the magnitude 3.5 earthquake near Ugashik, Alaska?

The magnitude 3.5 earthquake that struck 45 km ESE of Ugashik, Alaska on May 19, 2025 at 23:43 UTC had a depth of 106.1 km. It was felt by 2 people with maximum shaking intensity of MMI 3.2 (light). 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.

Understanding This Data

Magnitude 3.5 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: ak0256e9nisx). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, May 19, 2025). M3.5 Earthquake 45 km ESE of Ugashik, AlaskaMay 19, 2025. Retrieved July 25, 2025 from https://www.earthquaketracker.org/earthquakes/event/ak0256e9nisx/