official (US Geological Survey, event us6000u4j2, ShakeMap and PAGER, Oct 24; USGS earthquake catalog, Oct 23 to 24)
An M6.9 quake opens a swarm off Vanuatu, with dozens of strong shocks since
The first shock was the largest. It did not stop there. USGS has counted 29 earthquakes of magnitude 4.5 or more in the same patch of sea since early Saturday.
Key facts
- Magnitude
- M6.9 (Mww), reviewed origin (USGS)
- Time
- Oct 24, 02:31:28 UTC; 10:31 PM ET Oct 23; 1:31 PM local Oct 24 (USGS)
- Location
- 197 km west northwest of Port-Olry, Vanuatu, at sea (USGS)
- Depth
- 10 km, operator assigned (USGS)
- PAGER
- Green alert (USGS)
- Shaking
- ShakeMap estimates a maximum intensity of about MMI V (USGS)
- Sequence
- M6.3 at 02:35 UTC; M5.7 at 04:05; M5.8 at 04:12; M5.8 at 05:23; M5.9 at 08:56 UTC, all at 10 km and near the main shock (USGS)
- Count
- 29 earthquakes of M4.5 or more in the area from 21:00 UTC Oct 23 to 12:45 UTC Oct 24, including the M6.9 (USGS catalog)
M 6.9, 197 km WNW of Port-Olry, Vanuatu
US Geological Survey, event us6000u4j2, Oct 24
Note
A magnitude 6.9 earthquake struck at sea west northwest of Vanuatu's Espiritu Santo at 02:31 UTC on Saturday, October 24, the US Geological Survey says. It was 1:31 PM local time and 10:31 PM Friday in New York. USGS places it 197 km west northwest of Port-Olry, at a depth of 10 km.
Four minutes later an M6.3 struck nearby. Over the next six hours USGS logged an M5.7, two M5.8 shocks and an M5.9, all at the same shallow depth and within a few tens of kilometers of the main shock.
By 12:45 UTC the USGS catalog listed 29 earthquakes of magnitude 4.5 or more in the area since Friday evening UTC. Eighteen were M5.0 or larger, and seven were M5.5 or more.
The PAGER system issued a green alert, and the ShakeMap estimate for the main shock tops out at about intensity V, moderate shaking, because the epicenter is far out at sea.
The sea floor here is still moving. The count is still climbing.
Why it matters
Vanuatu sits on one of the most active plate boundaries on Earth. A shallow M6.9 followed within minutes by an M6.3 and then by a long run of strong shocks means the fault has not finished moving, and USGS counts are still rising.
Sources
- US Geological Survey: M 6.9, 197 km WNW of Port-Olry, Vanuatu, event us6000u4j2 (Oct 24 2026)
- US Geological Survey: PAGER assessment for us6000u4j2 (Oct 24 2026)
- US Geological Survey: earthquake catalog search, M4.5 and larger near Vanuatu (Oct 24 2026)
Primary + secondary attribution as listed.
More: Earthquakes
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