QuakeIndex

explosion · reviewed by a seismologist

M 1.6ml

Earthquake near Forest Grove, OR

No earthquake was likely felt in Forest Grove in the 24 hours to 8:02 pm PST (04:02 UTC). The last one was M 2.2, 9 km (5 mi) N, at 1:37 pm PDT on 1 October 2025, estimated intensity II (weak) in town. Every earthquake near Forest Grove

No: USGS classifies this as a explosion, not an earthquake. A magnitude 1.6 explosion was recorded 21 km (13 mi) west of Forest Grove, OR, at 12:45 pm PDT on 18 August 2025 (19:45 UTC), less than 1 km deep.

USGS: 21 km W of Forest Grove, Oregon

57 km (35 mi) W of Portland, OR · 34 km (21 mi) W of Hillsboro, OR

12:45 pm PDT, Aug 18, 2025 · · -0.6 km deep · released about 6.8 lb of TNT

10 km30 km60 km120 km N Washington County 22 kmTillamook County 32 kmYamhill County 34 kmColumbia County 49 kmClatsop County 58 kmPolk County 73 kmClark County 73 kmMultnomah County 75 kmWahkiakum County 83 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
12:45 pm PDT on 18 August 2025 ()
Where
21 km (13 mi) west of Forest Grove, OR · earthquakes near Forest Grove
Magnitude
M 1.6 (ml)
Depth
-0.6 km below the surface
Felt
no reports yet
Nearest
Washington County, 22 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 443 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 Forest Grove, 21 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: Banks, Cornelius, Yamhill.

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 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 45.5523, -123.3763. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Washington County, OR 22 km (13 mi) E earthquakes near Washington County
Tillamook County, OR 32 km (20 mi) WSW earthquakes near Tillamook County
Yamhill County, OR 34 km (21 mi) S earthquakes near Yamhill County
Columbia County, OR 49 km (30 mi) NNE earthquakes near Columbia County
Clatsop County, OR 58 km (36 mi) NNW earthquakes near Clatsop County
Polk County, OR 73 km (45 mi) S earthquakes near Polk County

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

Aftershocks so far

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

  1. 1.7 13 km WSW of Vernonia, Oregon
  2. 1.6 26 km W of Banks, Oregon
  3. 1.7 27 km E of Wheeler, Oregon
  4. 1.2 4 km ENE of Lafayette, Oregon
  5. 1.0 7 km NW of Yamhill, Oregon
  6. 0.9 6 km WNW of King City, Oregon
  7. 1.4 11 km NE of Vernonia, Oregon
  8. 0.9 11 km NNW of Vernonia, Oregon
  9. 1.1 4 km ENE of Lafayette, Oregon
  10. 1.4 9 km SSE of Scappoose, Oregon
  11. 2.0 10 km SSE of Scappoose, Oregon
  12. 1.6 8 km SW of Vernonia, Oregon
  13. 1.9 21 km W of Forest Grove, Oregon
  14. 2.0 7 km WNW of McMinnville, Oregon
  15. 1.5 5 km WNW of King City, Oregon

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.