M1.7 Earthquake near South Hills, Montana — 29 July 2026
A micro earthquake of magnitude 1.7 was recorded near South Hills, Montana on , with an epicentre 0 km north-northwest of South Hills, at a focal depth of 5.8 km.
Time (UTC): 2026-07-29 18:27:54
Time (your timezone): —
Magnitude: 1.7 (micro)
Focal depth: 5.8 km (shallow)
Epicentre: 46.5590, -111.9990
Location: 0 km NNW of South Hills, Montana
USGS link to NOAA tsunami information: Not linked
Review status: Reviewed
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 1.7 earthquake radiates roughly 5.2 kg of TNT equivalent in seismic energy.
The USGS assigns this earthquake a significance score of 44, 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.
Where was the epicentre?
The epicentre was located at 46.5590, -111.9990 — 0 km north-northwest of South Hills. The closest other recorded event was a magnitude 2.4 earthquake 12 km south-southeast of here on 20 May 2026.
Why the 6 km depth matters
At 6 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.
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 M1.7 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 in the 3 days since this event.
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 M1.7 event released about 5,821 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 July 2026 worldwide record. Browse the full monthly archive to compare periods.
Nearest recorded earthquakes to this epicentre
- M2.4 earthquake near Clancy, Montana — (12 km SSE)
- M1.7 earthquake near Marysville, Montana — (28 km WNW)
- M2.0 earthquake near Helena Valley Northeast, Montana — (36 km NNE)
- M1.6 earthquake near Townsend, Montana — (42 km ESE)
- M1.5 earthquake near Helena Valley Northeast, Montana — (43 km NE)
- M1.5 earthquake near Craig, Montana — (48 km N)
- M0.9 earthquake near Lincoln, Montana — (52 km NW)
- M0.9 earthquake near Lincoln, Montana — (54 km NW)
- M1.2 earthquake near Lincoln, Montana — (55 km NW)
- M2.2 earthquake near Lincoln, Montana — (56 km WNW)
Other magnitude 1 earthquakes worldwide
- M1.5 earthquake near Jal, New Mexico —
- M1.7 earthquake near Pāhala, Hawaii —
- M1.6 earthquake near Pedro Bay, Alaska —
- M1.5 earthquake near Lamont, CA —
- M1.7 earthquake near Progreso, B.C., MX —
- M2.0 earthquake near Avalon, CA —
- M1.6 earthquake near Progreso, B.C., MX —
- M1.8 earthquake near Toyah, Texas —
Questions about this earthquake
How strong is a magnitude 1.7 earthquake?
Micro earthquakes are almost never felt at the surface and are recorded only by seismographs. A magnitude 1.7 earthquake radiates roughly 5.2 kg of TNT equivalent in seismic energy.
How deep was the earthquake near South Hills?
At 6 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.
Was the M1.7 earthquake near South Hills felt?
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.
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 M1.7 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 in the 3 days since this event.
How often do earthquakes happen near South Hills?
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 M1.7 event released about 5,821 times less energy than that event.