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M4.2 Earthquake near False Pass, United States — 19 September 2025, 02:58 UTC

A light earthquake of magnitude 4.2 was recorded near False Pass, United States on , with an epicentre 223 km south-southeast of False Pass, at a focal depth of 10.0 km. It ranked as the 42nd strongest of 7496 earthquakes recorded in the United States in the preceding 30 days.

4.2 Light

Time (UTC): 2025-09-19 02:58:15

Time (your timezone): —

Magnitude: 4.2 (light)

Focal depth: 10.0 km (shallow)

Epicentre: 53.0581, -161.8970

Location: 223 km SSE of False Pass, Alaska

Country: United States

USGS link to NOAA tsunami information: Not linked

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 4.2 earthquake radiates roughly 30 tons of TNT equivalent in seismic energy.

The USGS assigns this earthquake a significance score of 271, 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 16:10 local solar time at the epicentre, during the afternoon.

This event was deeper than 69% of the 161,355 earthquakes recorded in the United States in our catalogue and stronger than 100% of them.

Where was the epicentre?

The epicentre was located at 53.0581, -161.8970 — 223 km south-southeast of False Pass. The closest other recorded event was a magnitude 3.4 earthquake 9 km northwest of here on 28 August 2026.

The nearest other settlements in our records are Akutan (110 km southwest) and Cold Bay (224 km north-northwest).

Why the 10 km depth matters

At 10 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 record does not carry a link to NOAA tsunami information. That field is not an all-clear and does not state whether a tsunami occurred. In this case, a damaging tsunami would be less likely because at M4.2 it falls below the magnitude 6.5 threshold that generally applies before a submarine earthquake displaces enough water to generate a damaging tsunami; it occurred inland rather than beneath the sea floor. For an active coastal alert, use tsunami.gov or your local warning authority.

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

Aftershocks and local seismic history

1 further earthquakes have been recorded within about 150 km of the epicentre in the seven days after this event, the largest of them magnitude 3.8.

76 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 7.3 event near Sand Point on 16 July 2025. This M4.2 event released about 44,668 times less energy than that event.

4 earthquakes have been recorded within 100 km of this epicentre in the past year, 0 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 September 2025 worldwide record, and of earthquakes in the United States during September 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 False Pass?

It measured magnitude 4.2 — a light earthquake. A magnitude 4.2 earthquake radiates roughly 30 tons of TNT equivalent in seismic energy.

How deep was the earthquake near False Pass?

The focus was 10 km below the surface, which counts as shallow.

Was the False Pass earthquake felt at the surface?

At magnitude 4.2 and a focal depth of 10 km, shaking would have been concentrated near the epicentre.

When did the earthquake near False Pass happen?

19 September 2025 at 02:58 UTC.

Was there a tsunami?

No. The USGS record carries no tsunami-information link for this event.

Have there been aftershocks?

1 further earthquakes have been recorded within about 150 km of the epicentre in the seven days after this event, the largest of them magnitude 3.8.

How often do earthquakes happen near False Pass?

76 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 7.3 event near Sand Point on 16 July 2025. This M4.2 event released about 44,668 times less energy than that event.