explosion · reviewed by a seismologist
M 1.8ml
Earthquake near Tri-Cities, WA
USGS: 12 km SSW of Tri-Cities, Washington
9 km (6 mi) SW of Kennewick, WA
- When
- 3:13 pm PDT on 22 September 2021 ()
- Where
- 12 km (8 mi) SSW of Tri-Cities, WA · earthquakes near Tri-Cities
- Magnitude
- M 1.8 (ml)
- Depth
- -0.3 km below the surface
- Felt
- no reports yet
- Nearest
- Benton County, 21 km WNW
- Nearest mapped fault
- Wallula fault system, 11 km from its surface trace — near is not the same as on
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1831 days ago
A magnitude 1.8 earthquake was recorded 12 km (8 mi) SSW of Tri-Cities, WA, at 3:13 pm PDT on 22 September 2021 (22:13 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
Earthquakes near other towns within 30 km: Highland, Kennewick, West Pasco, Richland, Pasco, Finley.
USGS catalogues this as explosion, not an earthquake.
How big was it?
This earthquake released about 14 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.
- Mineral, Virginia 2011 M 5.8 1,100,000× the energy of this one
- Magna, Utah 2020 M 5.7 760,000× the energy of this one
- Around the size people start to feel M 3.0 68× the energy of this one
- This earthquake M 1.8 about 14 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 46.1485, -119.2733. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Benton County, WA | 21 km (13 mi) | WNW | earthquakes near Benton County |
| Franklin County, WA | 52 km (32 mi) | NNE | earthquakes near Franklin County |
| Walla Walla County, WA | 62 km (39 mi) | E | earthquakes near Walla Walla County |
| Umatilla County, OR | 75 km (46 mi) | SE | earthquakes near Umatilla County |
| Morrow County, OR | 84 km (52 mi) | SSW | earthquakes near Morrow County |
| Columbia County, WA | 106 km (66 mi) | E | earthquakes near Columbia County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
59 earthquakes have been recorded within 50 km since this one.
- 1.6 4 km S of Echo, Oregon
- 1.7 10 km SSW of Tri-Cities, Washington
- 2.0 4 km SE of Umatilla, Oregon
- 1.6 10 km ENE of Prosser, Washington
- 1.7 6 km E of Wallula, Washington
- 1.6 17 km NNE of Pasco, Washington
- 2.2 4 km SE of Benton City, Washington
- 1.8 3 km N of Highland, Washington
- 1.6 6 km W of Highland, Washington
- 1.8 4 km SSW of West Richland, Washington
- 1.9 11 km WNW of Highland, Washington
- 1.7 14 km S of Benton City, Washington
- 2.8 4 km S of Richland, Washington
- 1.7 4 km SSW of West Richland, Washington
- 1.7 5 km ENE of Prosser, Washington
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.