4.1

M4.1 Earthquake in the Mariana Islands regionAugust 4, 2026

2026-08-04 22:18:29 UTC (2026-08-04) · approx. 8:18 AM UTC+10 local

MagnitudeM4.1(mb)
Time22:18 UTC8:18 AM UTC+10
Depth376.7 kmdeep-focus
Coordinates21.637°, 142.961°
Felt byNo felt reports
Status✓ Reviewed by USGS

On August 4, 2026 at 22:18 UTC, a magnitude 4.1 deep-focus earthquake struck in the Mariana Islands region, at a depth of 376.7 km and coordinates 21.6371°, 142.9606°.

Physical scale: An earthquake of magnitude 4.1 releases seismic energy equivalent to roughly 21 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 406 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 21.64°, 142.96°

Earthquake Details

Magnitude
4.1 mb
Depth
376.7 km
deep-focus
Location
21.6371°N
142.9606°E

Technical Information

Event ID
us6000tj0f
Event Type
earthquake
Status
✓ Reviewed
Significance
259
Stations Used
26
Azimuthal Gap
120.0°
Min Station Distance
6.912°
RMS Residual
0.63 sec
Last Updated
2026-08-18 00:10:12 UTC

Common Questions

How strong was the magnitude 4.1 earthquake in the Mariana Islands region?

The magnitude 4.1 earthquake that struck in the Mariana Islands region on August 4, 2026 at 22:18 UTC had a depth of 376.7 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 4.1 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.1 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us6000tj0f). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, August 4, 2026). M4.1 Earthquake in the Mariana Islands regionAugust 4, 2026. Retrieved August 18, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000tj0f/