4.4

M4.4 Earthquake 70 km WNW of Sinabang, IndonesiaAugust 21, 2021

2021-08-21 22:34:00 UTC (2021-08-21) · approx. 4:34 AM UTC+6 local

MagnitudeM4.4(mb)
Time22:34 UTC4:34 AM UTC+6
Depth25.0 kmshallow crustal
Coordinates2.635°, 95.763°
Felt byNo felt reports
Status✓ Reviewed by USGS

On August 21, 2021 at 22:34 UTC, a magnitude 4.4 shallow crustal earthquake struck 70 km WNW of Sinabang, Indonesia, at a depth of 25.0 km and coordinates 2.6354°, 95.7626°.

Physical scale: An earthquake of magnitude 4.4 releases seismic energy equivalent to roughly 60 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 655 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 2.64°, 95.76°

Earthquake Details

Magnitude
4.4 mb
Depth
25.0 km
shallow crustal
Location
2.6354°N
95.7626°E

Technical Information

Event ID
us6000f9fh
Event Type
earthquake
Status
✓ Reviewed
Significance
298
Azimuthal Gap
194.0°
Min Station Distance
2.243°
RMS Residual
0.62 sec
Last Updated
2021-11-02 14:54:08 UTC

Common Questions

How strong was the magnitude 4.4 earthquake near Sinabang, Indonesia?

The magnitude 4.4 earthquake that struck 70 km WNW of Sinabang, Indonesia on August 21, 2021 at 22:34 UTC had a depth of 25.0 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 4.4 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.4 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us6000f9fh). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, August 21, 2021). M4.4 Earthquake 70 km WNW of Sinabang, IndonesiaAugust 21, 2021. Retrieved November 2, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000f9fh/