M4.7 Earthquake in the Kepulauan Mentawai region, Indonesia — April 22, 2023
2023-04-22 23:11:15 UTC (2023-04-22) · approx. 6:11 AM UTC+7 local
Aftershock of the M5.6 mainshock.
On April 22, 2023 at 23:11 UTC, a magnitude 4.7 shallow crustal earthquake struck in the Kepulauan Mentawai region, Indonesia, at a depth of 16.3 km and coordinates -1.0392°, 98.3974°. This earthquake was detected by 62 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 340, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.7 releases seismic energy equivalent to roughly 169 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.1 km — a useful intuition for the size of the slip patch on the fault.
This earthquake is part of an ongoing aftershock sequence following the magnitude 5.6 mainshock that occurred 13 days ago 154 km SSE of Teluk Dalam, Indonesia. Since the mainshock, the USGS has recorded 0 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
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
Earthquake Details
98.3974°E
Technical Information
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Common Questions
How strong was the magnitude 4.7 earthquake in the Kepulauan Mentawai region, Indonesia?
The magnitude 4.7 earthquake that struck in the Kepulauan Mentawai region, Indonesia on April 22, 2023 at 23:11 UTC had a depth of 16.3 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at -1.0392°, 98.3974°, which is in the Kepulauan Mentawai region, Indonesia. View all earthquakes in Indonesia.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.7 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.6 one earlier?
No. This magnitude 4.7 earthquake is an aftershock of the larger magnitude 5.6 mainshock that occurred earlier 154 km SSE of Teluk Dalam, Indonesia. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
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 4.7 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us6000k6gg). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, April 22, 2023). M4.7 Earthquake in the Kepulauan Mentawai region, Indonesia — April 22, 2023. Retrieved July 3, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000k6gg/