Earthquake.now

M3.9 Earthquake near Happy Valley, United States — 29 August 2026

A minor earthquake of magnitude 3.9 was recorded near Happy Valley, United States on , with an epicentre 26 km west of Happy Valley, at a focal depth of 92.1 km. It ranked as the 58th strongest of 7720 earthquakes recorded in the United States in the preceding 30 days.

3.9 Minor

Time (UTC): 2026-08-29 12:02:11

Time (your timezone): —

Magnitude: 3.9 (minor)

Focal depth: 92.1 km (intermediate)

Epicentre: 59.9260, -152.2130

Location: 26 km W of Happy Valley, Alaska

Country: United States

USGS link to NOAA tsunami information: Not linked

Review status: Automatic

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 3.9 earthquake radiates roughly 11 tons of TNT equivalent in seismic energy.

The USGS assigns this earthquake a significance score of 238, 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 59.9260, -152.2130 — 26 km west of Happy Valley. The closest other recorded event was a magnitude 2.6 earthquake 20 km southwest of here on 27 August 2026.

Why the 92 km depth matters

At 92 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 M3.9 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

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

41 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 M3.9 event released about 1,413 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 August 2026 worldwide record, and of earthquakes in the United States during August 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 3 earthquakes worldwide

All magnitude 3 earthquakes →

Questions about this earthquake

How strong is a magnitude 3.9 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 3.9 earthquake radiates roughly 11 tons of TNT equivalent in seismic energy.

How deep was the earthquake near Happy Valley?

At 92 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 M3.9 earthquake near Happy Valley 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 M3.9 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.

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 Happy Valley?

41 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 M3.9 event released about 1,413 times less energy than that event.