EARTHQUAKEM5.5

M5.5 earthquake near Port-Olry, Vanuatu

Map: the earthquake near Port-Olry, Vanuatu, with plate boundaries

A magnitude 5.5 earthquake struck 221 km (137 mi) northwest of Port-Olry, Vanuatu on Wednesday, October 28, 2026 at 01:39 UTC, at a depth of 10 km (6 mi), according to the U.S. Geological Survey. Shallow quakes like this one shake the surface hardest.

USGS’s PAGER impact estimate is GREEN: little or no damage expected.

MagnitudeM5.5
Depth10 km (6 mi)
Time (UTC)Oct 28 01:39
Location13.89°S 165.39°E
Nearest townPort-Olry · 221 km
Energy3 kilotons TNT
Aftershocks M2.5+2
Tsunami flagNo
PAGER alertGREEN
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Why here?

This earthquake struck about 83 km (52 mi) from the boundary between the Pacific and Australian plates. Most earthquakes happen along plate boundaries like this one, where the pieces of Earth’s outer shell collide, pull apart or grind past each other. Stress builds up over years until the rock suddenly slips.

The red lines on the map are plate boundaries.

What kind of fault?

USGS’s analysis of the seismic waves shows it was a normal-fault earthquake: the crust was being stretched, and one block dropped down relative to the other.

Shaking and impact

USGS’s PAGER system estimates it most likely caused no deaths (90 percent probability). Early estimates are revised as reports come in.

How strong was it?

Magnitude is logarithmic: each whole step releases about 32 times more energy. This magnitude 5.5 released roughly the energy of 3 kilotons of TNT. That is about 178 times the energy of a magnitude 4.0, a quake people nearby feel but that rarely causes damage. The strongest earthquake ever recorded, magnitude 9.5 in Chile in 1960, released about 1,000,000 times more than this one.

Aftershocks

In the first 1 hour after it, USGS recorded 2 smaller earthquakes of magnitude 2.5 or more within 100 km (62 mi). The largest was a magnitude 5.2 on October 28 at 02:17 UTC.

A stronger magnitude 6.0 followed on October 28 at 02:21 UTC, about 7 km (5 mi) away, so this one is now considered a foreshock.

Outside the United States, USGS mainly lists quakes of about magnitude 4 and up, so smaller aftershocks there are undercounted.

Earthquake history here

Before this earthquake, USGS had recorded 302 earthquakes of magnitude 6 or larger within 300 km (186 mi) since 1900. The strongest:

Official details, updates and the shaking map: USGS event page.

See every earthquake on October 28, 2026 or earthquakes by day.

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