M5.0 Earthquake near Halmahera, Indonesia — March 17, 2021
2021-03-17 16:20:49 UTC (2021-03-17) · approx. 1:20 AM UTC+9 local
Aftershock of the M5.6 mainshock.
On March 17, 2021 at 16:20 UTC, a magnitude 5.0 intermediate depth earthquake struck near Halmahera, Indonesia, at a depth of 93.6 km and coordinates 2.2695°, 128.3103°.
Physical scale: An earthquake of magnitude 5.0 releases seismic energy equivalent to roughly 477 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.7 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 16 days ago 78 km NNE of Tobelo, 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
128.3103°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 5.0 earthquake near Halmahera, Indonesia?
The magnitude 5.0 earthquake that struck near Halmahera, Indonesia on March 17, 2021 at 16:20 UTC had a depth of 93.6 km. For context, this was a moderate earthquake that could be widely felt.
Where did the earthquake occur?
The earthquake epicenter was located at 2.2695°, 128.3103°, which is near Halmahera, Indonesia. View all earthquakes in Indonesia.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.0 earthquakes can continue for days to weeks and gradually diminish over time.
Is this the same earthquake as the M5.6 one earlier?
No. This magnitude 5.0 earthquake is an aftershock of the larger magnitude 5.6 mainshock that occurred earlier 78 km NNE of Tobelo, 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 5.0 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us7000dkb2). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, March 17, 2021). M5.0 Earthquake near Halmahera, Indonesia — March 17, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000dkb2/