EARTHQUAKEM4.6

M4.6 earthquake near Inarajan Village, Guam

Map: the earthquake near Inarajan Village, Guam, with plate boundaries

A magnitude 4.6 earthquake struck 22 mi (36 km) south of Inarajan Village, Guam on Sunday, October 18, 2026 at 17:28 UTC, at a depth of 28 mi (44 km), according to the U.S. Geological Survey. Shallow quakes like this one shake the surface hardest.

MagnitudeM4.6
Depth28 mi (44 km)
Time (UTC)Oct 18 17:28
Location12.94°N 144.74°E
Nearest townInarajan Village · 36 km
Energy120 tons TNT
Aftershocks M2.5+0
Tsunami flagNo
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Why here?

This earthquake struck about 56 mi (90 km) from the boundary between the Pacific and Philippine Sea 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.

How strong was it?

Magnitude is logarithmic: each whole step releases about 32 times more energy. This magnitude 4.6 released roughly the energy of 120 tons of TNT. That is about 7.9 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 22,000,000 times more than this one.

Aftershocks

In the first 7 days after it, USGS recorded no smaller earthquakes of magnitude 2.5 or more within 62 mi (100 km).

Earthquake history here

Before this earthquake, USGS had recorded 48 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 18, 2026 or earthquakes by day.

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