explosion · reviewed by a seismologist
M 2.1ml
Earthquake near Colfax, WA
USGS: 11 km SW of Colfax, Washington
97 km (60 mi) S of Spokane, WA
- When
- 3:00 pm PDT on 28 May 2020 ()
- Where
- 11 km (7 mi) SW of Colfax, WA · earthquakes near Colfax
- Magnitude
- M 2.1 (ml)
- Depth
- -1.1 km below the surface
- Felt
- no reports yet
- Nearest
- Whitman County, 13 km NNW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2317 days ago
A magnitude 2.1 earthquake was recorded 11 km (7 mi) SW of Colfax, WA, at 3:00 pm PDT on 28 May 2020 (22:00 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
Earthquakes near other towns within 30 km: Pullman.
USGS catalogues this as explosion, not an earthquake.
How big was it?
This earthquake released about 38 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 390,000× the energy of this one
- Magna, Utah 2020 M 5.7 280,000× the energy of this one
- Around the size people start to feel M 3.0 25× the energy of this one
- This earthquake M 2.1 about 38 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 46.7987, -117.4565. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Whitman County, WA | 13 km (8 mi) | NNW | earthquakes near Whitman County |
| Garfield County, WA | 42 km (26 mi) | S | earthquakes near Garfield County |
| Latah County, ID | 55 km (34 mi) | E | earthquakes near Latah County |
| Columbia County, WA | 66 km (41 mi) | SSW | earthquakes near Columbia County |
| Asotin County, WA | 71 km (44 mi) | SSE | earthquakes near Asotin County |
| Nez Perce County, ID | 74 km (46 mi) | SE | earthquakes near Nez Perce County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
30 earthquakes have been recorded within 50 km since this one.
- 2.1 5 km ENE of Pullman, Washington
- 1.7 4 km E of Uniontown, Washington
- 2.3 4 km ENE of Pullman, Washington
- 1.8 7 km SSW of Tekoa, Washington
- 1.7 15 km NW of Pomeroy, Washington
- 2.3 5 km SSW of Moscow, Idaho
- 1.6 8 km SSE of Pullman, Washington
- 2.2 8 km SW of Potlatch, Idaho
- 1.8 14 km E of Pomeroy, Washington
- 2.1 5 km NNE of Pullman, Washington
- 2.0 2 km NE of Colfax, Washington
- 1.9 8 km SSE of Pullman, Washington
- 2.3 3 km ESE of Pullman, Washington
- 2.0 16 km WNW of Pomeroy, Washington
- 1.6 5 km WNW of Genesee, Idaho
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
- 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.