QuakeIndex

explosion · reviewed by a seismologist

M 1.6ml

Earthquake near Kalama, WA

No earthquake was likely felt in Kalama in the 24 hours to 7:50 am PST (15:50 UTC). The last one was M 3.0, 14 km (8 mi) S, at 7:25 am PDT on 22 October 2026, estimated intensity II (weak) in town; 113 felt reports to USGS. Every earthquake near Kalama

No: USGS classifies this as a explosion, not an earthquake. A magnitude 1.6 explosion was recorded 5 km (3 mi) north-northeast of Kalama, WA, at 8:15 am PST on 12 December 2023 (16:15 UTC), less than 1 km deep.

USGS: 5 km NNE of Kalama, Washington

58 km (36 mi) NNW of Portland, OR · 49 km (30 mi) NNW of Vancouver, WA

8:15 am PST, Dec 12, 2023 · · -0.2 km deep · released about 7.3 lb of TNT

10 km30 km60 km120 km N Cowlitz County 20 kmColumbia County 24 kmClark County 40 kmWahkiakum County 55 kmWashington County 59 kmMultnomah County 63 kmSkamania County 66 kmLewis County 68 kmClatsop County 69 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
8:15 am PST on 12 December 2023 ()
Where
5 km (3 mi) north-northeast of Kalama, WA · earthquakes near Kalama
Magnitude
M 1.6 (ml)
Depth
-0.2 km below the surface
Felt
no reports yet
Nearest
Cowlitz County, 20 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1067 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 Kalama, 5 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: Rainier, Kelso, Longview, Woodland, West Side Highway, Columbia City.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 7.3 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 2,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,500,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.3 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 46.0475, -122.8120. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Cowlitz County, WA 20 km (12 mi) NNE earthquakes near Cowlitz County
Columbia County, OR 24 km (15 mi) WSW earthquakes near Columbia County
Clark County, WA 40 km (25 mi) SE earthquakes near Clark County
Wahkiakum County, WA 55 km (34 mi) WNW earthquakes near Wahkiakum County
Washington County, OR 59 km (37 mi) SSW earthquakes near Washington County
Multnomah County, OR 63 km (39 mi) SSE earthquakes near Multnomah County

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

Aftershocks so far

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

  1. 2.0 5 km NW of North Portland, Oregon
  2. 1.6 5 km ENE of Prescott, Oregon
  3. 1.6 6 km WSW of Castle Rock, Washington
  4. 1.5 14 km NE of Amboy, Washington
  5. 1.6 10 km NE of Castle Rock, Washington
  6. 1.6 10 km NE of Castle Rock, Washington
  7. 2.2 0 km SE of Barberton, Washington
  8. 1.5 24 km N of Amboy, Washington
  9. 2.0 30 km N of Amboy, Washington
  10. 1.6 1 km WSW of Kalama, Washington
  11. 1.7 24 km N of Amboy, Washington
  12. 2.1 24 km N of Amboy, Washington
  13. 1.7 4 km NNE of Kalama, Washington
  14. 1.6 19 km SSE of Mossyrock, Washington
  15. 1.6 18 km SSE of Mossyrock, 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.