QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Eureka, MT

No earthquake was likely felt in Eureka in the 24 hours to 12:45 pm MST (19:45 UTC). The last one was M 3.2, 39 km (24 mi) ESE, at 12:58 am MST on 3 January 2021, estimated intensity II (weak) in town. Every earthquake near Eureka

This page: a magnitude 1.5 earthquake was recorded in Eureka, MT, at 6:38 am MST on 28 November 2019 (13:38 UTC), 7.7 km deep.

USGS: 0 km NW of Eureka, Montana

6:38 am MST, Nov 28, 2019 · · 7.7 km deep · released about 5.6 lb of TNT

10 km30 km60 km120 km N Lincoln County 47 kmFlathead County 99 kmBoundary County 108 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
6:38 am MST on 28 November 2019 ()
Where
in Eureka, MT · earthquakes near Eureka
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 1.5 (ml)
Depth
7.7 km below the surface
Felt
no reports yet
Nearest
Lincoln County, 47 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2540 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 7 km (4 mi) from the epicentre. 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.

How big was it?

This earthquake released about 5.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,700,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
  3. Around the size people start to feel M 3.0 170× the energy of this one
  4. This earthquake M 1.5 about 5.6 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.

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 48.8848, -115.0597. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lincoln County, MT 47 km (29 mi) SW earthquakes near Lincoln County
Flathead County, MT 99 km (61 mi) SE earthquakes near Flathead County
Boundary County, ID 108 km (67 mi) W earthquakes near Boundary County
Bonner County, ID 131 km (81 mi) WSW earthquakes near Bonner County

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

Aftershocks so far

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

  1. 2.4 8 km ESE of Stryker, Montana
  2. 2.3 6 km NNE of Olney, Montana
  3. 2.2 19 km E of Indian Springs, Montana
  4. 1.8 20 km NW of West Kootenai, Montana
  5. 1.9 19 km NE of Indian Springs, Montana
  6. 1.5 30 km NE of Indian Springs, Montana
  7. 3.2 19 km ENE of Stryker, Montana
  8. 2.6 14 km NNE of Fortine, Montana
  9. 2.1 5 km NNE of Olney, 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.