QuakeIndex

explosion · reviewed by a seismologist

M 1.6ml

Earthquake near Yacolt, WA

No earthquake was likely felt in Yacolt in the 24 hours to 11:47 pm PST (07:47 UTC). The last one was M 1.6, 7 km (5 mi) SW, at 4:25 pm PDT on 19 October 2026, estimated intensity II (weak) in town. Every earthquake near Yacolt

No: USGS classifies this as a explosion, not an earthquake. A magnitude 1.6 explosion was recorded 3 km (2 mi) west-southwest of Yacolt, WA, at 2:53 pm PDT on 16 September 2020 (21:53 UTC), less than 1 km deep.

USGS: 3 km WSW of Yacolt, Washington

39 km (24 mi) NNE of Portland, OR · 27 km (17 mi) NNE of Vancouver, WA

2:53 pm PDT, Sep 16, 2020 · · -0.9 km deep · released about 6.8 lb of TNT

10 km30 km60 km120 km N Clark County 10 kmMultnomah County 35 kmCowlitz County 42 kmSkamania County 42 kmColumbia County 50 kmWashington County 61 kmHood River County 73 kmClackamas County 80 kmLewis County 80 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
2:53 pm PDT on 16 September 2020 ()
Where
3 km (2 mi) west-southwest of Yacolt, WA · earthquakes near Yacolt
Magnitude
M 1.6 (ml)
Depth
-0.9 km below the surface
Felt
no reports yet
Nearest
Clark County, 10 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2248 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 11 km (7 mi) from the epicentre. In Yacolt, 3 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

Earthquakes near other towns within 30 km: Amboy, Lewisville, Venersborg, Battle Ground, Hockinson, Meadow Glade.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 6.8 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 2,200,000× 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 6.8 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 17 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.7 38 km NNE of Amboy, Washington · 44 km NNE of this epicentre
  2. 5.2 5 km E of Bridgeton, Oregon · 31 km SSW of this epicentre
  3. 5.2 37 km NNE of Amboy, Washington · 43 km NNE of this epicentre
  4. 5.1 28 km ENE of Amboy, Washington · 31 km NE of this epicentre
  5. 5.1 Washington · 46 km NNE 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 45.8582, -122.4473. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Clark County, WA 10 km (6 mi) SSW earthquakes near Clark County
Multnomah County, OR 35 km (21 mi) S earthquakes near Multnomah County
Cowlitz County, WA 42 km (26 mi) NNW earthquakes near Cowlitz County
Skamania County, WA 42 km (26 mi) ENE earthquakes near Skamania County
Columbia County, OR 50 km (31 mi) W earthquakes near Columbia County
Washington County, OR 61 km (38 mi) WSW earthquakes near Washington County

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

Aftershocks so far

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

  1. 1.7 1 km NNE of Battle Ground, Washington
  2. 1.8 2 km E of Saint Helens, Oregon
  3. 1.5 2 km WSW of Yacolt, Washington
  4. 1.5 7 km ENE of Prescott, Oregon
  5. 2.0 4 km SE of Mill Plain, Washington
  6. 2.1 11 km ENE of Prescott, Oregon
  7. 1.6 4 km NNW of Lewisville, Washington
  8. 2.6 3 km SE of Mill Plain, Washington
  9. 1.7 1 km WSW of Kalama, Washington
  10. 2.0 21 km E of Castle Rock, Washington
  11. 1.6 2 km ESE of Lewisville, Washington
  12. 2.0 37 km NNE of Amboy, Washington
  13. 2.8 21 km E of Castle Rock, Washington
  14. 1.5 21 km E of Castle Rock, Washington
  15. 2.5 21 km E of Castle Rock, 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.