4.3

M4.3 Earthquake 104 km SSE of Akhiok, AlaskaJuly 18, 2026

2026-07-18 07:20:42 UTC (50 min ago) · approx. 9:20 PM UTC-10 local

MagnitudeM4.3(ml)
Time07:20 UTC9:20 PM UTC-10
Depth37.1 kmshallow crustal
Coordinates56.124°, -153.339°
Felt byNo felt reports
Status✓ Reviewed by USGS

On July 18, 2026 at 07:20 UTC, a magnitude 4.3 shallow crustal earthquake struck 104 km SSE of Akhiok, Alaska, at a depth of 37.1 km and coordinates 56.1240°, -153.3390°.

Physical scale: An earthquake of magnitude 4.3 releases seismic energy equivalent to roughly 43 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 558 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 56.12°, -153.34°

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 M4.3 earthquake near 104 km SSE of Akhiok, Alaska

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

Earthquake Details

Magnitude
4.3 ml
Depth
37.1 km
shallow crustal
Location
56.1240°N
-153.3390°E
Intensity (MMI)
2.9
weak

Technical Information

Event ID
aka2026ochauu
Event Type
earthquake
Status
✓ Reviewed
Significance
284
Stations Used
178
Azimuthal Gap
176.0°
Min Station Distance
0.600°
RMS Residual
0.60 sec
Last Updated
2026-07-18 07:37:46 UTC

Common Questions

How strong was the magnitude 4.3 earthquake near Akhiok, Alaska?

The magnitude 4.3 earthquake that struck 104 km SSE of Akhiok, Alaska on July 18, 2026 at 07:20 UTC had a depth of 37.1 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 4.3 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.3 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: aka2026ochauu). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, July 18, 2026). M4.3 Earthquake 104 km SSE of Akhiok, AlaskaJuly 18, 2026. Retrieved July 18, 2026 from https://www.earthquaketracker.org/earthquakes/event/aka2026ochauu/