QuakeIndex

quarry blast · reviewed by a seismologist

M 1.8ml

Earthquake near Butte, MT

No earthquake was likely felt in Butte in the 24 hours to 11:56 pm MDT (05:56 UTC). The last one was M 1.5, 6 km (4 mi) E, at 1:01 pm MDT on 16 October 2026, estimated intensity II (weak) in town. Every earthquake near Butte

No: USGS classifies this as a quarry blast, not an earthquake. A magnitude 1.8 quarry blast was recorded 6 km (3 mi) east of Butte, MT, at 1:15 pm MDT on 15 October 2026 (19:15 UTC), less than 1 km deep.

USGS: 5 km E of Butte, Montana

1:15 pm MDT, Oct 15, 2026 · · -2.0 km deep · released about 13 lb of TNT

10 km30 km60 km120 km N Silver Bow County 20 kmJefferson County 34 kmDeer Lodge County 53 kmBroadwater County 82 kmGranite County 86 kmMadison County 87 kmPowell County 100 kmBeaverhead County 103 kmGallatin County 115 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
1:15 pm MDT on 15 October 2026 ()
Where
6 km (3 mi) east of Butte, MT · earthquakes near Butte
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 1.8 (ml)
Depth
-2.0 km below the surface
Felt
no reports yet
Nearest
Silver Bow County, 20 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 5 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 13 km (8 mi) from the epicentre. In Butte, 6 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

Likely felt in: Butte 6 km, intensity II. Estimated for each town centre; each link is that town's own record.

USGS catalogues this as quarry blast, not an earthquake.

How big was it?

This earthquake released about 13 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 840,000× the energy of this one
  3. Around the size people start to feel M 3.0 75× the energy of this one
  4. This earthquake M 1.8 about 13 lb of TNT

Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.

For this area

The largest earthquake within 50 km since 2016 was M 4.0 on 2016-09-03 — about 2,600 times the energy of this one.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.4 Near Butte, Montana · 3 km WSW of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 46.0088, -112.4622. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Silver Bow County, MT 20 km (12 mi) SW earthquakes near Silver Bow County
Jefferson County, MT 34 km (21 mi) ENE earthquakes near Jefferson County
Deer Lodge County, MT 53 km (33 mi) W earthquakes near Deer Lodge County
Broadwater County, MT 82 km (51 mi) ENE earthquakes near Broadwater County
Granite County, MT 86 km (53 mi) WNW earthquakes near Granite County
Madison County, MT 87 km (54 mi) SSE earthquakes near Madison County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

2 earthquakes have been recorded within 50 km since this one.

  1. 1.5 6 km E of Butte, Montana
  2. 1.6 15 km S of Whitehall, Montana

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.