5.5

M5.5 Earthquake in the Kepulauan Mentawai region, Indonesia — May 2, 2021

2021-05-02 17:46:41 UTC (2021-05-02) · approx. 12:46 AM UTC+7 local

Maximum shaking intensity MMI 5.2 (strong).

MagnitudeM5.5(mww)
Time17:46 UTC≈ 12:46 AM UTC+7
Depth21.0 kmshallow crustal
Coordinates-2.324°, 99.790°
Felt byNo felt reports
Status✓ Reviewed by USGS· green PAGER
green Alert— no significant casualties or damage expected

On May 2, 2021 at 17:46 UTC, a magnitude 5.5 shallow crustal earthquake struck in the Kepulauan Mentawai region, Indonesia, at a depth of 21.0 km and coordinates -2.3244°, 99.7900°. The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. The nearest populated place is Tuapejat (population 0).

Physical scale: An earthquake of magnitude 5.5 releases seismic energy equivalent to roughly 3 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 3.8 km — a useful intuition for the size of the slip patch on the fault.

The epicenter is located in Indonesia, a region characterized by the convergence of the Indo-Australian, Eurasian, and Philippine Sea plates, forming the Sunda-Banda arc system. The nearest mapped fault system is the Sunda megathrust. View all earthquakes in Indonesia.

Learn more: Magnitude scale · Aftershock sequences

Nearest Populated Places

Tuapejatpop. 0
MMI 3.7 (light)
Muara Siberutpop. 0
MMI 3.1 (light)
Kambangpop. 0
MMI 3.0 (weak)
Mandarahanpop. 0
MMI 2.9 (weak)
Pasarbarupop. 0
MMI 2.9 (weak)
Pasarkuokpop. 0
MMI 2.8 (weak)
Map showing earthquake epicenter at -2.32°, 99.79°

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 M5.5 earthquake near Kepulauan Mentawai region, Indonesia

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

Population exposure (USGS PAGER)

Estimated population that experienced each level of shaking. Based on the USGS PAGER rapid impact assessment, which combines ShakeMap output with global population grids.

Shaking intensity (MMI)DescriptionPopulation exposed
MMI 3weak2,786,232
MMI 4light18,666
MMI 5moderate8,136

Earthquake Details

Magnitude
5.5 mww
Depth
21.0 km
shallow crustal
Location
-2.3244°N
99.7900°E
Intensity (MMI)
5.2
strong

Technical Information

Event ID
us7000dziv
Event Type
earthquake
Status
✓ Reviewed
Significance
465
Azimuthal Gap
46.0°
Min Station Distance
2.914°
RMS Residual
1.09 sec
Last Updated
2025-12-22 18:57:48 UTC

Common Questions

How strong was the magnitude 5.5 earthquake in the Kepulauan Mentawai region, Indonesia?

The magnitude 5.5 earthquake that struck in the Kepulauan Mentawai region, Indonesia on May 2, 2021 at 17:46 UTC had a depth of 21.0 km. For context, this was a moderate earthquake that could be widely felt.

Where did the earthquake occur?

The earthquake epicenter was located at -2.3244°, 99.7900°, which is in the Kepulauan Mentawai region, Indonesia. The nearest populated place is Tuapejat (population 0). View all earthquakes in Indonesia.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.5 earthquakes can continue for days to weeks and gradually diminish over time.

Has Indonesia had earthquakes this big before?

The largest recorded earthquake in Indonesia was the M9.1 Indian Ocean earthquake of December 26, 2004. Today's magnitude 5.5 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us7000dziv). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, May 2, 2021). M5.5 Earthquake in the Kepulauan Mentawai region, Indonesia — May 2, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000dziv/