EARTHQUAKEM5.4

M5.4 earthquake near Ambunti, Papua New Guinea

Map: the earthquake near Ambunti, Papua New Guinea, with plate boundaries

A magnitude 5.4 earthquake struck 33 km (21 mi) east-southeast of Ambunti, Papua New Guinea on Sunday, October 25, 2026 at 10:30 UTC, at a depth of 72 km (45 mi), according to the U.S. Geological Survey. At this intermediate depth, shaking spreads out before it reaches the surface.

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

1 person reported feeling it to USGS “Did You Feel It?”.

MagnitudeM5.4
Depth72 km (45 mi)
Time (UTC)Oct 25 10:30
Location4.36°S 143.08°E
Nearest townAmbunti · 33 km
Energy2 kilotons TNT
Aftershocks M2.5+0
Tsunami flagNo
PAGER alertGREEN
Felt reports1
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Why here?

This earthquake struck about 140 km (87 mi) from the boundary between the Australian and Pacific 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. At 72 km down, it most likely broke inside a plate that is sinking into the mantle beneath its neighbor, in what geologists call a subduction zone.

The red lines on the map are plate boundaries.

Shaking and impact

The strongest shaking USGS estimates was intensity 4 on the Modified Mercalli scale: light. 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 5.4 released roughly the energy of 2 kilotons of TNT. That is about 126 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 1,400,000 times more than this one.

Aftershocks

In the first 24 hours after it, USGS recorded no smaller earthquakes of magnitude 2.5 or more within 100 km (62 mi).

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 119 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 25, 2026 or earthquakes by day.

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