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M2.1 Earthquake near Ponderosa Pines, United States — 17 August 2026, 08:17 UTC

A minor earthquake of magnitude 2.1 was recorded near Ponderosa Pines, United States on , with an epicentre 4 km northwest of Ponderosa Pines, at a focal depth of 3.5 km. It ranked as the 1145th strongest of 7175 earthquakes recorded in the United States in the preceding 30 days.

2.1 Minor

Time (UTC): 2026-08-17 08:17:05

Time (your timezone): —

Magnitude: 2.1 (minor)

Focal depth: 3.5 km (shallow)

Epicentre: 46.0585, -111.4160

Location: 4 km NW of Ponderosa Pines, Montana

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 2.1 earthquake radiates roughly 23 kg of TNT equivalent in seismic energy.

The USGS assigns this earthquake a significance score of 69, 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 00:51 local solar time at the epicentre, in the early hours of the morning.

This event was shallower than 68% of the 156,239 earthquakes recorded in the United States in our catalogue and stronger than 86% of them.

Where was the epicentre?

The epicentre was located at 46.0585, -111.4160 — 4 km northwest of Ponderosa Pines. The closest other recorded event was a magnitude 0.3 earthquake 139 km south of here on 14 September 2026.

The nearest other settlements in our records are Boulder (34 km west-northwest), Belgrade (35 km southeast), Amsterdam (39 km south) and Churchill (41 km south).

Why the 4 km depth matters

At 4 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, events this small are usually detected by instruments rather than people. 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 M2.1 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

8 further earthquakes have been recorded within about 150 km of the epicentre in the seven days after this event, the largest of them magnitude 1.4.

1 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 4.2 event near Black Eagle on 29 January 2026. This M2.1 event released about 1,318 times less energy than that event.

59 earthquakes have been recorded within 100 km of this epicentre in the past year, 4 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 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 2 earthquakes worldwide

All magnitude 2 earthquakes →

Questions about this earthquake

How strong was the earthquake near Ponderosa Pines?

It measured magnitude 2.1 — a minor earthquake. A magnitude 2.1 earthquake radiates roughly 23 kg of TNT equivalent in seismic energy.

How deep was the earthquake near Ponderosa Pines?

The focus was 4 km below the surface, which counts as shallow.

Was the Ponderosa Pines earthquake felt at the surface?

At magnitude 2.1 and a focal depth of 4 km, shaking would have been concentrated near the epicentre.

When did the earthquake near Ponderosa Pines happen?

17 August 2026 at 08:17 UTC.

Was there a tsunami?

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

Have there been aftershocks?

8 further earthquakes have been recorded within about 150 km of the epicentre in the seven days after this event, the largest of them magnitude 1.4.

How often do earthquakes happen near Ponderosa Pines?

1 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 4.2 event near Black Eagle on 29 January 2026. This M2.1 event released about 1,318 times less energy than that event.