4.2

M4.2 Earthquake 286 km W of Adak, Alaska — September 30, 2026

2026-09-30 19:10:09 UTC (2 hours ago) · approx. 7:10 AM UTC+12 local

MagnitudeM4.2(mb)
Time19:10 UTC≈ 7:10 AM UTC+12
Depth119.2 kmintermediate depth
Coordinates51.880°, 179.212°
Felt byNo felt reports
Status✓ Reviewed by USGS

On September 30, 2026 at 19:10 UTC, a magnitude 4.2 intermediate depth earthquake struck 286 km W of Adak, Alaska, at a depth of 119.2 km and coordinates 51.8805°, 179.2118°.

Physical scale: An earthquake of magnitude 4.2 releases seismic energy equivalent to roughly 30 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 476 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 51.88°, 179.21°

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 M4.2 earthquake near 286 km W of Adak, Alaska

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

Earthquake Details

Magnitude
4.2 mb
Depth
119.2 km
intermediate depth
Location
51.8805°N
179.2118°E
Intensity (MMI)
2.3
weak

Technical Information

Event ID
us6000tyl5
Event Type
earthquake
Status
✓ Reviewed
Significance
271
Stations Used
121
Azimuthal Gap
37.0°
Min Station Distance
0.256°
RMS Residual
0.86 sec
Last Updated
2026-09-30 20:53:05 UTC

Common Questions

How strong was the magnitude 4.2 earthquake near Adak, Alaska?

The magnitude 4.2 earthquake that struck 286 km W of Adak, Alaska on September 30, 2026 at 19:10 UTC had a depth of 119.2 km. 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 4.2 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.2 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us6000tyl5). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, September 30, 2026). M4.2 Earthquake 286 km W of Adak, Alaska — September 30, 2026. Retrieved September 30, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000tyl5/