M4.8 Earthquake 103 km NNE of Tobelo, Indonesia — March 17, 2021
2021-03-17 21:23:29 UTC (2021-03-17) · approx. 6:23 AM UTC+9 local
Aftershock of the M5.6 mainshock.
On March 17, 2021 at 21:23 UTC, a magnitude 4.8 intermediate depth earthquake struck 103 km NNE of Tobelo, Indonesia, at a depth of 202.6 km and coordinates 2.5456°, 128.4595°.
Physical scale: An earthquake of magnitude 4.8 releases seismic energy equivalent to roughly 239 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.2 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
128.4595°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.8 earthquake near Tobelo, Indonesia?
The magnitude 4.8 earthquake that struck 103 km NNE of Tobelo, Indonesia on March 17, 2021 at 21:23 UTC had a depth of 202.6 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 2.5456°, 128.4595°, which is 103 km NNE of Tobelo, Indonesia. View all earthquakes in Indonesia.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.8 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 4.8 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 4.8 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us7000dkdl). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, March 17, 2021). M4.8 Earthquake 103 km NNE of Tobelo, Indonesia — March 17, 2021. Retrieved May 26, 2021 from https://www.earthquaketracker.org/earthquakes/event/us7000dkdl/