M5.4 Earthquake 67 km SE of Kokopo, Papua New Guinea — August 23, 2020
2020-08-23 16:46:47 UTC (2020-08-23) · approx. 2:46 AM UTC+10 local
Aftershock of the M5.6 mainshock.
On August 23, 2020 at 16:46 UTC, a magnitude 5.4 shallow crustal earthquake struck 67 km SE of Kokopo, Papua New Guinea, at a depth of 47.4 km and coordinates -4.7912°, 152.6752°. The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. The nearest populated place is Rabaul (population 8,074).
Physical scale: An earthquake of magnitude 5.4 releases seismic energy equivalent to roughly 2 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 3.2 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 13 days ago 72 km ESE of Kokopo, Papua New Guinea. Since the mainshock, the USGS has recorded 2 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 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
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 | 389,992 |
| MMI 4 | light | 2,860 |
Earthquake Details
152.6752°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 5.4 earthquake near Kokopo, Papua New Guinea?
The magnitude 5.4 earthquake that struck 67 km SE of Kokopo, Papua New Guinea on August 23, 2020 at 16:46 UTC had a depth of 47.4 km. For context, this was a moderate earthquake that could be widely felt.
Where did the earthquake occur?
The earthquake epicenter was located at -4.7912°, 152.6752°, which is 67 km SE of Kokopo, Papua New Guinea. The nearest populated place is Rabaul (population 8,074). View all earthquakes in Papua New Guinea.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.4 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 5.4 earthquake is an aftershock of the larger magnitude 5.6 mainshock that occurred earlier 72 km ESE of Kokopo, Papua New Guinea. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
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 5.4 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us6000bjg0). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2020, August 23, 2020). M5.4 Earthquake 67 km SE of Kokopo, Papua New Guinea — August 23, 2020. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000bjg0/