QuakeIndex

explosion · reviewed by a seismologist

M 1.6ml

Earthquake near Boardman, OR

USGS: 21 km NE of Roosevelt, Washington

10:03 am PDT, Apr 12, 2021 · · -0.5 km deep · released about 6.4 lb of TNT

10 km30 km60 km120 km N Benton County 55 kmGilliam County 57 kmMorrow County 58 kmKlickitat County 60 kmSherman County 73 kmYakima County 87 kmUmatilla County 103 kmFranklin County 113 kmWasco County 119 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
10:03 am PDT on 12 April 2021 ()
Where
24 km (15 mi) W of Boardman, OR · earthquakes near Boardman
Magnitude
M 1.6 (ml)
Depth
-0.5 km below the surface
Felt
no reports yet
Nearest
Benton County, 55 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1995 days ago

A magnitude 1.6 earthquake was recorded 24 km (15 mi) W of Boardman, OR, at 10:03 am PDT on 12 April 2021 (17:03 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 6.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,400,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,700,000× the energy of this one
  3. Around the size people start to feel M 3.0 150× the energy of this one
  4. This earthquake M 1.6 about 6.4 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 45.8622, -120.0038. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Benton County, WA 55 km (34 mi) NE earthquakes near Benton County
Gilliam County, OR 57 km (36 mi) SSW earthquakes near Gilliam County
Morrow County, OR 58 km (36 mi) SSE earthquakes near Morrow County
Klickitat County, WA 60 km (37 mi) W earthquakes near Klickitat County
Sherman County, OR 73 km (46 mi) SW earthquakes near Sherman County
Yakima County, WA 87 km (54 mi) NW earthquakes near Yakima County

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

Aftershocks so far

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

  1. 1.5 17 km ENE of Roosevelt, Washington
  2. 2.1 12 km SSE of Bickleton, Washington
  3. 1.9 7 km SW of Arlington, Oregon
  4. 1.5 4 km SSW of Arlington, Oregon
  5. 1.7 8 km N of Roosevelt, Washington
  6. 1.5 17 km NNE of Roosevelt, Washington
  7. 1.5 13 km NNE of Roosevelt, Washington
  8. 1.9 16 km ENE of Arlington, Oregon
  9. 2.0 8 km SSE of Bickleton, Washington
  10. 2.0 2 km SSE of Arlington, Oregon
  11. 1.8 19 km NW of Bickleton, Washington
  12. 1.8 17 km ENE of Roosevelt, Washington
  13. 1.8 6 km SW of Arlington, Oregon
  14. 2.2 19 km S of Arlington, Oregon
  15. 1.9 11 km S of Bickleton, 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.