4.1

M4.1 Earthquake 229 km SSE of Amahai, IndonesiaApril 20, 2026

2026-04-20 21:45:25 UTC (2026-04-20) · approx. 6:45 AM UTC+9 local

MagnitudeM4.1(mb)
Time21:45 UTC6:45 AM UTC+9
Depth213.9 kmintermediate depth
Coordinates-5.255°, 129.723°
Felt byNo felt reports
Status✓ Reviewed by USGS

On April 20, 2026 at 21:45 UTC, a magnitude 4.1 intermediate depth earthquake struck 229 km SSE of Amahai, Indonesia, at a depth of 213.9 km and coordinates -5.2545°, 129.7229°.

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 -5.25°, 129.72°

Earthquake Details

Magnitude
4.1 mb
Depth
213.9 km
intermediate depth
Location
-5.2545°N
129.7229°E

Technical Information

Event ID
us7000sgzu
Event Type
earthquake
Status
✓ Reviewed
Significance
259
Stations Used
20
Azimuthal Gap
120.0°
Min Station Distance
0.749°
RMS Residual
0.53 sec
Last Updated
2026-05-12 23:42:40 UTC

Common Questions

How strong was the magnitude 4.1 earthquake near Amahai, Indonesia?

The magnitude 4.1 earthquake that struck 229 km SSE of Amahai, Indonesia on April 20, 2026 at 21:45 UTC had a depth of 213.9 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.

What should I do after an earthquake?

If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.

Authoritative source: USGS event page (event ID: us7000sgzu). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, April 20, 2026). M4.1 Earthquake 229 km SSE of Amahai, IndonesiaApril 20, 2026. Retrieved May 17, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000sgzu/