M6.9 Earthquake 222 km SSE of Katabu, Indonesia — August 21, 2020
2020-08-21 04:09:51 UTC (2020-08-21) · approx. 12:09 PM UTC+8 local
Felt by 38 people across nearby locations.
On August 21, 2020 at 04:09 UTC, a magnitude 6.9 deep-focus earthquake struck 222 km SSE of Katabu, Indonesia, at a depth of 624.0 km and coordinates -6.7100°, 123.4649°. The earthquake was reported felt by 38 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 2.8 (weak). The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. The nearest populated place is Muruona (population 0).
Physical scale: An earthquake of magnitude 6.9 releases seismic energy equivalent to roughly 338 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 35 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
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
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 38 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
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 | 1,658,404 |
Earthquake Details
123.4649°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 6.9 earthquake near Katabu, Indonesia?
The magnitude 6.9 earthquake that struck 222 km SSE of Katabu, Indonesia on August 21, 2020 at 04:09 UTC had a depth of 624.0 km. It was felt by 38 people with maximum shaking intensity of MMI 2.8 (weak). For context, this was a strong earthquake capable of causing significant damage.
Where did the earthquake occur?
The earthquake epicenter was located at -6.7100°, 123.4649°, which is 222 km SSE of Katabu, Indonesia. The nearest populated place is Muruona (population 0). View all earthquakes in Indonesia.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 6.9 earthquakes can continue for weeks to months 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 6.9 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us6000bi4p). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2020, August 21, 2020). M6.9 Earthquake 222 km SSE of Katabu, Indonesia — August 21, 2020. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000bi4p/