38 km ESE of Cardston, Canada

2020-04-20 19:30 UTC · 10 km deep · released about 120 lb of TNT

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: 2020-04-20 19:30 UTC
Magnitude: M 2.4 (ml)
Depth: 10 km below the surface
Felt: 1 report · strongest reported intensity II
Nearest: Glacier County, 35 km SSW
Status: Reviewed by a seismologist

USGS · last changed by USGS 2271 days ago · we first saw it 2271 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 1 person has reported feeling it to USGS.

How big was it?

This earthquake released about 120 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.

Mineral, Virginia 2011 M 5.8 130,000× the energy of this one
Magna, Utah 2020 M 5.7 89,000× the energy of this one
Around the size people start to feel M 3.0 7.9× the energy of this one
This earthquake M 2.4 about 120 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.

Where

Map loads when it scrolls into view

Epicentre 49.0089, -112.8574. Map © OpenStreetMap contributors.

Nearby places

Place	Distance	Direction
Glacier County, MT	35 km (22 mi)	NNE of here	earthquakes near Glacier County
Toole County, MT	92 km (57 mi)	WNW of here	earthquakes near Toole County
Pondera County, MT	99 km (61 mi)	NNW of here	earthquakes near Pondera County
Flathead County, MT	118 km (74 mi)	NE of here	earthquakes near Flathead County

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

Aftershocks so far

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

2.3 40 km SSE of Magrath, Canada 21:53 UTC
2.3 6 km SSW of Cardston, Canada 04:05 UTC
1.7 21 km SSE of Cardston, Canada 10:54 UTC
2.0 43 km NNW of Santa Rita, Montana 23:42 UTC
2.4 38 km NNW of Santa Rita, Montana 07:05 UTC
1.9 40 km SSE of Magrath, Canada 15:27 UTC
1.5 20 km NW of Santa Rita, Montana 03:06 UTC
2.7 17 km NNW of Santa Rita, Montana 02:59 UTC
2.8 8 km S of Cardston, Canada 22:10 UTC
1.7 14 km S of Cardston, Canada 14:52 UTC
2.0 Alberta, Canada 03:55 UTC
1.9 35 km SE of Cardston, Canada 12:15 UTC
1.5 23 km NW of Santa Rita, Montana 18:14 UTC
2.4 22 km NW of Santa Rita, Montana 20:46 UTC
2.1 42 km NW of Santa Rita, Montana 16:54 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 08:09 UTC. QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

On USGS

The official USGS event page — the source of record for every value above
Did you feel it? Report it to USGS — reports go to USGS, not to us
ShakeMap for this event, when USGS has produced one

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