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M1.4 Earthquake near Petersville, United States — 18 September 2026

A micro earthquake of magnitude 1.4 was recorded near Petersville, United States on , with an epicentre 60 km north of Petersville, at a focal depth of 123.5 km. It ranked as the 3670th strongest of 7534 earthquakes recorded in the United States in the preceding 30 days.

1.4 Micro

Time (UTC): 2026-09-18 23:43:33

Time (your timezone): —

Magnitude: 1.4 (micro)

Focal depth: 123.5 km (intermediate)

Epicentre: 63.0280, -150.9670

Location: 60 km N of Petersville, Alaska

Country: United States

USGS link to NOAA tsunami information: Not linked

Review status: Automatic

Source: USGS event page

How strong was this earthquake?

Micro earthquakes are almost never felt at the surface and are recorded only by seismographs.

A magnitude 1.4 earthquake radiates roughly 1.9 kg of TNT equivalent in seismic energy.

The USGS assigns this earthquake a significance score of 30, 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 13:39 local solar time at the epicentre, around midday.

This event was deeper than 99% of the 156,886 earthquakes recorded in the United States in our catalogue and stronger than 56% of them.

Where was the epicentre?

The epicentre was located at 63.0280, -150.9670 — 60 km north of Petersville. The closest other recorded event was a magnitude 2.3 earthquake 25 km west-northwest of here on 12 September 2026.

The nearest other settlements in our records are Anderson (151 km north-northeast), Beluga (218 km south) and Anchorage (226 km south-southeast).

Why the 124 km depth matters

At 124 km this was an intermediate-depth earthquake. Energy from events at this depth spreads out before it reaches the surface, which usually means weaker shaking near the epicentre than a shallow quake of the same magnitude, but shaking felt across a wider area.

This catalogue does not ingest eyewitness responses, so it cannot confirm where this earthquake was felt. Based on magnitude alone, events this small are usually detected by instruments rather than people. Its intermediate depth normally reduces peak shaking near the epicentre compared with a shallow 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 M1.4 it falls below the magnitude 6.5 threshold that generally applies before a submarine earthquake displaces enough water to generate a damaging tsunami; its 124 km focal depth is too great to deform the sea floor significantly; 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

No further earthquakes have been recorded within about 150 km of the epicentre since this event was recorded.

25 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 6.0 event near Susitna on 27 November 2025. This M1.4 event released about 7.9 million times less energy than that event.

1429 earthquakes have been recorded within 100 km of this epicentre in the past year, 79 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 2026 worldwide record, and of earthquakes in the United States during September 2026. 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 1 earthquakes worldwide

Questions about this earthquake

How strong was the earthquake near Petersville?

It measured magnitude 1.4 — a micro earthquake. A magnitude 1.4 earthquake radiates roughly 1.9 kg of TNT equivalent in seismic energy.

How deep was the earthquake near Petersville?

The focus was 124 km below the surface, which counts as intermediate.

Was the Petersville earthquake felt at the surface?

At magnitude 1.4 and a focal depth of 124 km, the depth spreads the energy out, so shaking is weaker overhead but reaches further.

When did the earthquake near Petersville happen?

18 September 2026 at 23:43 UTC.

Was there a tsunami?

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

Have there been aftershocks?

No further earthquakes have been recorded within about 150 km of the epicentre since this event was recorded.

How often do earthquakes happen near Petersville?

25 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 6.0 event near Susitna on 27 November 2025. This M1.4 event released about 7.9 million times less energy than that event.