M5.5 Earthquake 86 km ESE of Kokopo, Papua New Guinea — October 9, 2021
2021-10-09 20:01:51 UTC (2021-10-09) · approx. 6:01 AM UTC+10 local
Felt by 2 people across nearby locations.
On October 9, 2021 at 20:01 UTC, a magnitude 5.5 shallow crustal earthquake struck 86 km ESE of Kokopo, Papua New Guinea, at a depth of 54.0 km and coordinates -4.6376°, 152.9931°. The earthquake was reported felt by 2 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 3.9 (light). The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. The nearest populated place is Buka (population 0).
Physical scale: An earthquake of magnitude 5.5 releases seismic energy equivalent to roughly 3 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 3.8 km — a useful intuition for the size of the slip patch on the fault.
The epicenter is located in Papua New Guinea, a region characterized by the collision and subduction of the Pacific, Australian, and Solomon Sea plates. View all earthquakes in Papua New Guinea.
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 2 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 | 481,770 |
| MMI 4 | light | 8,333 |
Earthquake Details
152.9931°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 5.5 earthquake near Kokopo, Papua New Guinea?
The magnitude 5.5 earthquake that struck 86 km ESE of Kokopo, Papua New Guinea on October 9, 2021 at 20:01 UTC had a depth of 54.0 km. It was felt by 2 people with maximum shaking intensity of MMI 3.9 (light). For context, this was a moderate earthquake that could be widely felt.
Where did the earthquake occur?
The earthquake epicenter was located at -4.6376°, 152.9931°, which is 86 km ESE of Kokopo, Papua New Guinea. The nearest populated place is Buka (population 0). View all earthquakes in Papua New Guinea.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.5 earthquakes can continue for days to weeks and gradually diminish over time.
Has Papua New Guinea had earthquakes this big before?
The largest recorded earthquake in Papua New Guinea was the M8.0 New Britain earthquake of July 18, 1971. Today's magnitude 5.5 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us6000ftd2). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, October 9, 2021). M5.5 Earthquake 86 km ESE of Kokopo, Papua New Guinea — October 9, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000ftd2/