4.2

M4.2 Earthquake in the Mariana Islands regionAugust 20, 2026

2026-08-20 14:51:57 UTC (2026-08-20) · approx. 12:51 AM UTC+10 local

MagnitudeM4.2(mb)
Time14:51 UTC12:51 AM UTC+10
Depth207.4 kmintermediate depth
Coordinates21.958°, 143.020°
Felt byNo felt reports
Status✓ Reviewed by USGS

On August 20, 2026 at 14:51 UTC, a magnitude 4.2 intermediate depth earthquake struck in the Mariana Islands region, at a depth of 207.4 km and coordinates 21.9582°, 143.0202°.

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 21.96°, 143.02°

Earthquake Details

Magnitude
4.2 mb
Depth
207.4 km
intermediate depth
Location
21.9582°N
143.0202°E

Technical Information

Event ID
us7000tc6v
Event Type
earthquake
Status
✓ Reviewed
Significance
271
Stations Used
37
Azimuthal Gap
116.0°
Min Station Distance
5.171°
RMS Residual
0.65 sec
Last Updated
2026-08-29 19:55:10 UTC

Common Questions

How strong was the magnitude 4.2 earthquake in the Mariana Islands region?

The magnitude 4.2 earthquake that struck in the Mariana Islands region on August 20, 2026 at 14:51 UTC had a depth of 207.4 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: us7000tc6v). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, August 20, 2026). M4.2 Earthquake in the Mariana Islands regionAugust 20, 2026. Retrieved August 29, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000tc6v/