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M3.8 Earthquake near Healy, United States — 18 December 2024

A minor earthquake of magnitude 3.8 was recorded near Healy, United States on , with an epicentre 5 km east-northeast of Healy, at a focal depth of 107.3 km. It ranked as the 19th strongest of 8721 earthquakes recorded in the United States in the preceding 30 days.

3.8 Minor

Time (UTC): 2024-12-18 04:44:36

Time (your timezone): —

Magnitude: 3.8 (minor)

Focal depth: 107.3 km (intermediate)

Epicentre: 63.8725, -148.8570

Location: 5 km ENE of Healy, Alaska

Country: United States

USGS link to NOAA tsunami information: Not linked

Review status: Reviewed

Source: USGS event page

How strong was this earthquake?

Minor earthquakes in this range are felt by people close to the epicentre as a brief jolt or rattle, but they very rarely cause any damage.

A magnitude 3.8 earthquake radiates roughly 7.6 tons of TNT equivalent in seismic energy.

The USGS assigns this earthquake a significance score of 222, 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 →

Where was the epicentre?

The epicentre was located at 63.8725, -148.8570 — 5 km east-northeast of Healy. The closest other recorded event was a magnitude 0.9 earthquake 49 km north-northeast of here on 01 August 2026.

Why the 107 km depth matters

At 107 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, an event this size may be noticed locally, especially close to the epicentre. 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 M3.8 it falls below the magnitude 6.5 threshold that generally applies before a submarine earthquake displaces enough water to generate a damaging tsunami; its 107 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

41 further earthquakes have been recorded within about 150 km of the epicentre in the seven days after this event, the largest of them magnitude 2.4.

10 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 5.0 event near Denali National Park on 28 July 2026. This M3.8 event released about 63 times less energy than that event.

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

Where this event sits in the record

This earthquake is part of the December 2024 worldwide record, and of earthquakes in the United States during December 2024. 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 3 earthquakes worldwide

All magnitude 3 earthquakes →

Questions about this earthquake

How strong is a magnitude 3.8 earthquake?

Minor earthquakes in this range are felt by people close to the epicentre as a brief jolt or rattle, but they very rarely cause any damage. A magnitude 3.8 earthquake radiates roughly 7.6 tons of TNT equivalent in seismic energy.

How deep was the earthquake near Healy?

At 107 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.

Was the M3.8 earthquake near Healy felt?

This catalogue does not ingest eyewitness responses, so it cannot confirm where this earthquake was felt. Based on magnitude alone, an event this size may be noticed locally, especially close to the epicentre. Its intermediate depth normally reduces peak shaking near the epicentre compared with a shallow event of the same magnitude.

What does the USGS tsunami field mean for this event?

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 M3.8 it falls below the magnitude 6.5 threshold that generally applies before a submarine earthquake displaces enough water to generate a damaging tsunami; its 107 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.

Have there been aftershocks?

41 further earthquakes have been recorded within about 150 km of the epicentre in the seven days after this event, the largest of them magnitude 2.4.

How often do earthquakes happen near Healy?

10 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 5.0 event near Denali National Park on 28 July 2026. This M3.8 event released about 63 times less energy than that event.