M5.6 Earthquake 247 km NE of Lospalos, Timor Leste — December 16, 2021
2021-12-16 04:26:06 UTC (2021-12-16) · approx. 1:26 PM UTC+9 local
Maximum shaking intensity MMI 6.1 (very strong). Aftershock of the M5.9 mainshock.
On December 16, 2021 at 04:26 UTC, a magnitude 5.6 shallow crustal earthquake struck 247 km NE of Lospalos, Timor Leste, at a depth of 10.0 km and coordinates -7.0438°, 128.6847°. The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. The nearest populated place is Tiakur (population 0).
Physical scale: An earthquake of magnitude 5.6 releases seismic energy equivalent to roughly 4 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 4.4 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 5.9 mainshock that occurred 6 days ago 253 km ENE of Lospalos, Timor Leste. 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.
Nearest Populated Places
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.
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) | Description | Population exposed |
|---|---|---|
| MMI 3 | weak | 139,399 |
| MMI 4 | light | 203 |
| MMI 5 | moderate | 271 |
| MMI 6 | strong | 530 |
Earthquake Details
128.6847°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 5.6 earthquake near Lospalos, Timor Leste?
The magnitude 5.6 earthquake that struck 247 km NE of Lospalos, Timor Leste on December 16, 2021 at 04:26 UTC had a depth of 10.0 km. For context, this was a moderate earthquake that could be widely felt.
Where did the earthquake occur?
The earthquake epicenter was located at -7.0438°, 128.6847°, which is 247 km NE of Lospalos, Timor Leste. The nearest populated place is Tiakur (population 0).
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.6 earthquakes can continue for days to weeks and gradually diminish over time.
Is this the same earthquake as the M5.9 one earlier?
No. This magnitude 5.6 earthquake is an aftershock of the larger magnitude 5.9 mainshock that occurred earlier 253 km ENE of Lospalos, Timor Leste. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
Actions
Authoritative source: USGS event page (event ID: us6000gcnj). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, December 16, 2021). M5.6 Earthquake 247 km NE of Lospalos, Timor Leste — December 16, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000gcnj/