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M4.8 Earthquake near Atka, United States — 09 November 2025, 09:36 UTC

A light earthquake of magnitude 4.8 was recorded near Atka, United States on , with an epicentre 190 km east of Atka, at a focal depth of 43.4 km. It ranked as the 11th strongest of 5859 earthquakes recorded in the United States in the preceding 30 days.

4.8 Light

Time (UTC): 2025-11-09 09:36:50

Time (your timezone): —

Magnitude: 4.8 (light)

Focal depth: 43.4 km (shallow)

Epicentre: 52.1699, -171.4090

Location: 190 km E of Atka, Alaska

Country: United States

USGS link to NOAA tsunami information: Available

Review status: Reviewed

Source: USGS event page

How strong was this earthquake?

Light earthquakes are widely felt near the epicentre and can rattle windows, dishes and hanging objects. Damage is uncommon and usually limited to cracked plaster or fallen loose items.

A magnitude 4.8 earthquake radiates roughly 239 tons of TNT equivalent in seismic energy.

The USGS assigns this earthquake a significance score of 354, which is below the USGS threshold of more than 600 for its significant-earthquake list. The ranking combines magnitude with available Did You Feel It responses and PAGER alert level; it is not a direct measurement of damage.

What the magnitude scale actually measures →

When it happened locally

That is about 22:11 local solar time at the epicentre, late at night.

This event was deeper than 92% of the 161,567 earthquakes recorded in the United States in our catalogue and stronger than 100% of them.

Where was the epicentre?

The epicentre was located at 52.1699, -171.4090 — 190 km east of Atka. The closest other recorded event was a magnitude 3.2 earthquake 22 km east of here on 19 August 2026.

The nearest other settlement in our records is Nikolski (189 km south-southeast).

Why the 43 km depth matters

At 43 km this was a shallow earthquake. Shallow events release their energy close to the surface, so for a given magnitude they produce noticeably stronger shaking — and more damage — than deeper ones. Roughly three quarters of all earthquakes worldwide occur at shallow depths.

This catalogue does not ingest eyewitness responses, so it cannot confirm where this earthquake was felt. Based on magnitude alone, an event this size is often felt across the surrounding area. Its shallow focus makes stronger surface shaking more likely than for a deeper event of the same magnitude.

Read more on how focal depth changes what you feel →

What does the tsunami information flag mean?

The USGS event record links to NOAA tsunami information because this was a large event in an oceanic region. That link flag does not mean a tsunami occurred or that a warning is active. Check tsunami.gov and instructions from your local authority for the current status of your coastline.

How earthquakes generate tsunamis, and what the alert levels mean →

Aftershocks and local seismic history

5 further earthquakes have been recorded within about 150 km of the epicentre in the seven days after this event, the largest of them magnitude 4.0.

111 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 6.5 event near Nikolski on 17 September 2026. This M4.8 event released about 355 times less energy than that event.

21 earthquakes have been recorded within 100 km of this epicentre in the past year, 3 of them in the past 30 days.

How long aftershock sequences last, and how large they get →

Where this event sits in the record

This earthquake is part of the November 2025 worldwide record, and of earthquakes in the United States during November 2025. Browse the full monthly archive to compare periods.

Nearest recorded earthquakes to this epicentre

Other recent earthquakes in the United States

All recorded earthquakes in the United States →

Other magnitude 4 earthquakes worldwide

All magnitude 4 earthquakes →

Questions about this earthquake

How strong was the earthquake near Atka?

It measured magnitude 4.8 — a light earthquake. A magnitude 4.8 earthquake radiates roughly 239 tons of TNT equivalent in seismic energy.

How deep was the earthquake near Atka?

The focus was 43 km below the surface, which counts as shallow.

Was the Atka earthquake felt at the surface?

At magnitude 4.8 and a focal depth of 43 km, shaking would have been concentrated near the epicentre.

When did the earthquake near Atka happen?

09 November 2025 at 09:36 UTC.

Was there a tsunami?

The USGS record carries a link to NOAA tsunami information for this event. That is not a warning: check your regional tsunami warning centre for any live alert.

Have there been aftershocks?

5 further earthquakes have been recorded within about 150 km of the epicentre in the seven days after this event, the largest of them magnitude 4.0.

How often do earthquakes happen near Atka?

111 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 6.5 event near Nikolski on 17 September 2026. This M4.8 event released about 355 times less energy than that event.