QuakeIndex

explosion · reviewed by a seismologist

M 1.6ml

Earthquake near Pomeroy, WA

USGS: 14 km NW of Pomeroy, Washington

2:49 pm PST, Jan 18, 2022 · · -0.6 km deep · released about 7.1 lb of TNT

10 km30 km60 km120 km N Garfield County 22 kmColumbia County 32 kmWhitman County 42 kmAsotin County 58 kmWalla Walla County 65 kmAdams County 77 kmNez Perce County 80 kmLatah County 83 kmFranklin County 88 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
2:49 pm PST on 18 January 2022 ()
Where
15 km (9 mi) NW of Pomeroy, WA · earthquakes near Pomeroy
Magnitude
M 1.6 (ml)
Depth
-0.6 km below the surface
Felt
no reports yet
Nearest
Garfield County, 22 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 571 days ago

A magnitude 1.6 earthquake was recorded 15 km (9 mi) NW of Pomeroy, WA, at 2:49 pm PST on 18 January 2022 (22:49 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 7.1 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,500,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.1 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 46.5592, -117.7548. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Garfield County, WA 22 km (14 mi) SE earthquakes near Garfield County
Columbia County, WA 32 km (20 mi) SSW earthquakes near Columbia County
Whitman County, WA 42 km (26 mi) NNE earthquakes near Whitman County
Asotin County, WA 58 km (36 mi) SE earthquakes near Asotin County
Walla Walla County, WA 65 km (40 mi) WSW earthquakes near Walla Walla County
Adams County, WA 77 km (48 mi) NW earthquakes near Adams County

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

Aftershocks so far

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

  1. 1.9 6 km WSW of Dayton, Washington
  2. 1.7 15 km NW of Pomeroy, Washington
  3. 1.6 5 km SW of Dayton, Washington
  4. 1.8 14 km E of Pomeroy, Washington
  5. 1.7 6 km WSW of Dayton, Washington
  6. 2.0 2 km NE of Colfax, Washington
  7. 2.0 16 km WNW of Pomeroy, Washington
  8. 1.7 6 km WSW of Dayton, Washington
  9. 1.6 7 km SW of Dayton, Washington
  10. 1.9 7 km WSW of Dayton, Washington
  11. 1.7 7 km ENE of Waitsburg, Washington
  12. 1.8 7 km ENE of Waitsburg, Washington
  13. 1.8 5 km E of Waitsburg, Washington
  14. 1.6 7 km WSW of Dayton, Washington
  15. 1.9 7 km ENE of Waitsburg, 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

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