M5.1 Earthquake — Guam Region

Measurements

Measured by

Earthquake data courtesy of EMSC

This is a scientific measurement of an event that has already happened. It is not a warning, and it does not tell you what to do.

Not rated by source. European-Mediterranean Seismological Centre does not publish a severity for this; the level shown is our own classification.

View original report

Also reported by: USGS

This event as JSON · API and licence

Source updated 39 days ago (Sep 10, 2026 13:52 UTC) · we last heard from European-Mediterranean Seismological Centre 34 seconds ago

What has changed

• Magnitude revised from M5.2 to M5.1 — Sep 10, 13:49 UTC by European-Mediterranean Seismological Centre

Figures published in the first minutes of an event are preliminary. A change here is the agency refining its own estimate, not a correction to this page.

What USGS has published since this earthquake

Aftershock forecast

USGS gives less than a 1% chance of at least one aftershock of magnitude 5 or larger in the week to 22 Oct 2026, less than a 1% chance of magnitude 6 or larger, and less than a 1% chance of magnitude 7 or larger.

USGS puts less than a 1% chance on an earthquake larger than this magnitude 5.1 following in the week to 22 Oct 2026.

USGS forecast issued 15 Oct 2026 13:28 UTC, generated automatically. A forecast gives chances, not times: it cannot say when or where an aftershock will strike.

Shaking and its likely impact

USGS estimates fewer than 1,000 people were exposed to strong shaking or worse (intensity VI and above).

USGS's PAGER system gives a green alert for deaths, meaning a low likelihood of casualties; and a green alert for economic losses, meaning a low likelihood of damage. These are estimates from a model of the shaking and the population it reached, not a count.

USGS PAGER, automatic.

Reports of the shaking

USGS received 4 "Did You Feel It?" reports; the strongest shaking reported was intensity II (weak).

How far the shaking reached

• Moderate shaking (intensity V) or more reached about 10 km from the epicentre at its farthest.
• Light shaking (intensity IV) or more reached about 30 km from the epicentre at its farthest.

USGS ShakeMap, automatic: an estimate built from seismic stations, felt reports and a model where there are neither. Distances are in a straight line from USGS's epicentre; the lines on the map above are USGS's contours, simplified. Shaking varies with the ground, so a place inside a line may have felt less or more.

From the U.S. Geological Survey. The USGS event page has the maps and everything USGS has published for this earthquake.

General safety information

No authority has issued instructions for this event. The guidance below is general background reading, not a response to it.

Drop, Cover, and Hold On — what to do before, during and after an earthquake, plus emergency kit and family plan checklists.

Open Earthquake Safety Guide →