QuakeIndex

explosion · reviewed by a seismologist

M 2.0ml

Earthquake near Milton-Freewater, OR

USGS: 4 km NE of Weston, Oregon

7:04 am PDT, Sep 22, 2017 · · -0.7 km deep · released about 36 lb of TNT

10 km30 km60 km120 km N Umatilla County 39 kmWalla Walla County 47 kmColumbia County 62 kmUnion County 67 kmFranklin County 87 kmGarfield County 92 kmAsotin County 96 kmWallowa County 96 kmBenton County 98 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
7:04 am PDT on 22 September 2017 ()
Where
10 km (6 mi) S of Milton-Freewater, OR · earthquakes near Milton-Freewater
Magnitude
M 2.0 (ml)
Depth
-0.7 km below the surface
Felt
no reports yet
Nearest
Umatilla County, 39 km SW
Nearest mapped fault
Wallula fault system, 2 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 3297 days ago

A magnitude 2.0 earthquake was recorded 10 km (6 mi) S of Milton-Freewater, OR, at 7:04 am PDT on 22 September 2017 (14:04 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: Athena, College Place, Garrett, Walla Walla East, Walla Walla.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 36 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.0 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 420,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 300,000× the energy of this one
  3. Around the size people start to feel M 3.0 27× the energy of this one
  4. This earthquake M 2.0 about 36 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 · 21 km N 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 45.8418, -118.3753. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Umatilla County, OR 39 km (24 mi) SW earthquakes near Umatilla County
Walla Walla County, WA 47 km (29 mi) N earthquakes near Walla Walla County
Columbia County, WA 62 km (38 mi) NE earthquakes near Columbia County
Union County, OR 67 km (41 mi) SSE earthquakes near Union County
Franklin County, WA 87 km (54 mi) NNW earthquakes near Franklin County
Garfield County, WA 92 km (57 mi) NE earthquakes near Garfield County

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

Aftershocks so far

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

  1. 1.8 3 km W of Pendleton, Oregon
  2. 2.1 5 km S of Milton-Freewater, Oregon
  3. 2.0 10 km W of Pendleton, Oregon
  4. 2.3 7 km N of Helix, Oregon
  5. 1.7 8 km N of Helix, Oregon
  6. 1.9 9 km WNW of Touchet, Washington
  7. 1.8 4 km NNW of Pendleton, Oregon
  8. 1.6 11 km E of Milton-Freewater, Oregon
  9. 1.7 11 km E of Milton-Freewater, Oregon
  10. 2.0 4 km ESE of Milton-Freewater, Oregon
  11. 1.5 22 km NNE of Elgin, Oregon
  12. 1.7 4 km N of Touchet, Washington
  13. 1.6 19 km SE of Walla Walla East, Washington
  14. 1.7 6 km E of Wallula, Washington
  15. 1.9 5 km NE of Dixie, 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.