Earthquake.now

M6.3 Earthquake near Nikolski, United States — 23 February 2026, 05:11 UTC

A strong earthquake of magnitude 6.3 was recorded near Nikolski, United States on , with an epicentre 91 km southwest of Nikolski, at a focal depth of 1.0 km. It ranked as the 2nd strongest of 7069 earthquakes recorded in the United States in the preceding 30 days.

6.3 Strong

Time (UTC): 2026-02-23 05:11:48

Time (your timezone): —

Magnitude: 6.3 (strong)

Focal depth: 1.0 km (shallow)

Epicentre: 52.4640, -169.9690

Location: 91 km SW of Nikolski, Alaska

Country: United States

USGS link to NOAA tsunami information: Available

Review status: Reviewed

Source: USGS event page

How strong was this earthquake?

Strong earthquakes can cause significant damage in populated areas within roughly 100 km of the epicentre, particularly to older masonry buildings. Landslides and liquefaction become a real risk in susceptible ground.

A magnitude 6.3 earthquake radiates roughly 42,502 tons of TNT equivalent in seismic energy.

The USGS assigns this earthquake a significance score of 611, which meets 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 17:51 local solar time at the epicentre, during the afternoon.

This event was shallower than 91% of the 155,669 earthquakes recorded in the United States in our catalogue and stronger than 100% of them.

Where was the epicentre?

The epicentre was located at 52.4640, -169.9690 — 91 km southwest of Nikolski. The closest other recorded event was a magnitude 2.6 earthquake 6 km east of here on 04 September 2026.

The nearest other settlements in our records are Atka (183 km south-southwest) and Dutch Harbor (204 km northeast).

Why the 1 km depth matters

At 1 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 can produce strong, widely felt shaking. 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

86 further earthquakes have been recorded within about 150 km of the epicentre in the seven days after this event, the largest of them magnitude 5.5.

148 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 6.3 event near Nikolski on 03 September 2026. This M6.3 event released a comparable amount of energy to that event.

167 earthquakes have been recorded within 100 km of this epicentre in the past year, 12 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 February 2026 worldwide record, and of earthquakes in the United States during February 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 6 earthquakes worldwide

All magnitude 6 earthquakes →

Questions about this earthquake

How strong was the earthquake near Nikolski?

It measured magnitude 6.3 — a strong earthquake. A magnitude 6.3 earthquake radiates roughly 42,502 tons of TNT equivalent in seismic energy.

How deep was the earthquake near Nikolski?

The focus was 1 km below the surface, which counts as shallow.

Was the Nikolski earthquake felt at the surface?

At magnitude 6.3 and a focal depth of 1 km, shaking would have been concentrated near the epicentre.

When did the earthquake near Nikolski happen?

23 February 2026 at 05:11 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?

86 further earthquakes have been recorded within about 150 km of the epicentre in the seven days after this event, the largest of them magnitude 5.5.

How often do earthquakes happen near Nikolski?

148 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 6.3 event near Nikolski on 03 September 2026. This M6.3 event released a comparable amount of energy to that event.