M5.8 Earthquake 37 km NW of Port-Olry, Vanuatu — January 11, 2023
2023-01-11 08:39:52 UTC (2023-01-11) · approx. 7:39 PM UTC+11 local
Maximum shaking intensity MMI 5.5 (strong). Aftershock of the M6.1 mainshock.
On January 11, 2023 at 08:39 UTC, a magnitude 5.8 shallow crustal earthquake struck 37 km NW of Port-Olry, Vanuatu, at a depth of 15.0 km and coordinates -14.7604°, 166.8762°. The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. This earthquake was detected by 120 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 518, placing it among routine seismic activity. The nearest populated place is Port-Olry (population 1,951).
Physical scale: An earthquake of magnitude 5.8 releases seismic energy equivalent to roughly 8 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 6.1 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 6.1 mainshock that occurred 19 days ago 56 km NNE of Port-Olry, Vanuatu. Since the mainshock, the USGS has recorded 2 aftershocks in this area. Aftershock activity is expected to continue for weeks to months as stresses on surrounding faults redistribute.
The epicenter is located in Vanuatu, a region characterized by the New Hebrides subduction zone, where the Australian Plate subducts eastward at approximately 90 mm per year. View all earthquakes in Vanuatu.
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 | 94,701 |
| MMI 4 | light | 59,308 |
| MMI 5 | moderate | 3,269 |
| MMI 6 | strong | 703 |
Earthquake Details
166.8762°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 5.8 earthquake near Port-Olry, Vanuatu?
The magnitude 5.8 earthquake that struck 37 km NW of Port-Olry, Vanuatu on January 11, 2023 at 08:39 UTC had a depth of 15.0 km. For context, this was a moderate earthquake that could be widely felt.
Where did the earthquake occur?
The earthquake epicenter was located at -14.7604°, 166.8762°, which is 37 km NW of Port-Olry, Vanuatu. The nearest populated place is Port-Olry (population 1,951). View all earthquakes in Vanuatu.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.8 earthquakes can continue for days to weeks and gradually diminish over time.
Is this the same earthquake as the M6.1 one earlier?
No. This magnitude 5.8 earthquake is an aftershock of the larger magnitude 6.1 mainshock that occurred earlier 56 km NNE of Port-Olry, Vanuatu. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
Has Vanuatu had earthquakes this big before?
The largest recorded earthquake in Vanuatu was the M7.9 Vanuatu earthquake of October 7, 2009. Today's magnitude 5.8 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us7000j3ky). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, January 11, 2023). M5.8 Earthquake 37 km NW of Port-Olry, Vanuatu — January 11, 2023. Retrieved March 20, 2023 from https://www.earthquaketracker.org/earthquakes/event/us7000j3ky/