QuakeIndex

explosion · reviewed by a seismologist

M 1.6ml

Earthquake near Tri-Cities, WA

USGS: 8 km ESE of Wallula, Washington

33 km (20 mi) ESE of Kennewick, WA

4:48 pm PDT, Sep 30, 2020 · · -0.4 km deep · released about 6.6 lb of TNT

10 km30 km60 km120 km N Walla Walla County 33 kmUmatilla County 52 kmFranklin County 54 kmBenton County 58 kmColumbia County 73 kmMorrow County 94 kmUnion County 104 kmGarfield County 106 kmAdams 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
4:48 pm PDT on 30 September 2020 ()
Where
37 km (23 mi) SE of Tri-Cities, WA · earthquakes near Tri-Cities
Magnitude
M 1.6 (ml)
Depth
-0.4 km below the surface
Felt
no reports yet
Nearest
Walla Walla County, 33 km NE
Nearest mapped fault
Wallula fault system, 3 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 2192 days ago

A magnitude 1.6 earthquake was recorded 37 km (23 mi) SE of Tri-Cities, WA, at 4:48 pm PDT on 30 September 2020 (23:48 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: Finley, Burbank, Highland.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 6.6 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 2,300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,600,000× the energy of this one
  3. Around the size people start to feel M 3.0 140× the energy of this one
  4. This earthquake M 1.6 about 6.6 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 lists one earthquake of M5 or more within 50 km:

  1. 6.0 3 km SW of Garrett, Washington · 29 km E of this epicentre

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 46.0575, -118.7997. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Walla Walla County, WA 33 km (20 mi) NE earthquakes near Walla Walla County
Umatilla County, OR 52 km (32 mi) S earthquakes near Umatilla County
Franklin County, WA 54 km (34 mi) N earthquakes near Franklin County
Benton County, WA 58 km (36 mi) WNW earthquakes near Benton County
Columbia County, WA 73 km (45 mi) ENE earthquakes near Columbia County
Morrow County, OR 94 km (58 mi) SW earthquakes near Morrow 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. 2.0 2 km WSW of Burbank, Washington
  2. 1.8 4 km SSE of Kennewick, Washington
  3. 1.7 10 km SSW of Tri-Cities, Washington
  4. 2.0 4 km SE of Umatilla, Oregon
  5. 1.7 4 km N of Touchet, Washington
  6. 1.7 6 km E of Wallula, Washington
  7. 1.6 17 km NNE of Pasco, Washington
  8. 1.8 3 km N of Highland, Washington
  9. 1.6 6 km W of Highland, Washington
  10. 1.7 9 km ESE of Echo, Oregon
  11. 1.9 11 km WNW of Highland, Washington
  12. 2.1 2 km ENE of Milton-Freewater, Oregon
  13. 2.8 4 km S of Richland, Washington
  14. 1.9 3 km WNW of Pendleton, Oregon
  15. 1.7 15 km S of Mesa, 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.