QuakeIndex

explosion · reviewed by a seismologist

M 2.0ml

Earthquake near Seattle, WA

No earthquake was likely felt in Seattle in the 24 hours to 11:19 am PST (19:19 UTC). The last one was M 4.2, 37 km (23 mi) SW, at 2:05 pm PDT on 29 September 2026, estimated intensity III (weak) in town; 9,329 felt reports to USGS. Every earthquake near Seattle

No: USGS classifies this as a explosion, not an earthquake. A magnitude 2.0 explosion was recorded 32 km (20 mi) west-southwest of Seattle, WA, at 3:18 pm PST on 20 February 2023 (23:18 UTC), less than 1 km deep.

USGS: 3 km WNW of Gorst, Washington

31 km (19 mi) WSW of Seattle, WA

3:18 pm PST, Feb 20, 2023 · · -0.2 km deep · released about 33 lb of TNT

10 km30 km60 km120 km N Kitsap County 14 kmMason County 38 kmJefferson County 65 kmThurston County 67 kmKing County 69 kmIsland County 69 kmPierce County 70 kmSnohomish County 93 kmGrays Harbor County 94 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
3:18 pm PST on 20 February 2023 ()
Where
32 km (20 mi) west-southwest of Seattle, WA · earthquakes near Seattle
Magnitude
M 2.0 (ml)
Depth
-0.2 km below the surface
Felt
no reports yet
Nearest
Kitsap County, 14 km NNE
Nearest mapped fault
Seattle fault, 3 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 1360 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 16 km (10 mi) from the epicentre. In Seattle, 32 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.

Likely felt in: Bremerton 9 km, intensity II · Enetai 12 km, intensity II · Silverdale 13 km, intensity II. Estimated for each town centre; each link is that town's own record.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 33 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 5.8 450,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 320,000× the energy of this one
  3. Around the size people start to feel M 3.0 29× the energy of this one
  4. This earthquake M 2.0 about 33 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

The largest earthquake within 50 km since 2016 was M 4.1 on 2017-02-23 — about 1,200 times the energy of this one.

Before 2016, the USGS record lists 6 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.8 The 2001 Nisqually, Washington Earthquake · 43 km S of this epicentre
  2. 6.7 1 km ENE of Dash Point, Washington · 35 km SE of this epicentre
  3. 6.1 Puget Sound region, Washington · 15 km S of this epicentre
  4. 5.8 Puget Sound area, Washington · 31 km SSW of this epicentre
  5. 5.3 Eastern Olympic Peninsula, Washington · 35 km NNW 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 47.5382, -122.7492. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Kitsap County, WA 14 km (8 mi) NNE earthquakes near Kitsap County
Mason County, WA 38 km (24 mi) WSW earthquakes near Mason County
Jefferson County, WA 65 km (41 mi) WNW earthquakes near Jefferson County
Thurston County, WA 67 km (42 mi) S earthquakes near Thurston County
King County, WA 69 km (43 mi) E earthquakes near King County
Island County, WA 69 km (43 mi) N earthquakes near Island County

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

Aftershocks so far

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

  1. 3.1 Puget Sound region, Washington
  2. 1.8 4 km SW of Port Ludlow, Washington
  3. 2.3 0 km WSW of Bothell West, Washington
  4. 1.7 3 km ENE of Bainbridge Island, Washington
  5. 2.1 3 km SSE of Quilcene, Washington
  6. 2.1 10 km WNW of Longbranch, Washington
  7. 1.5 2 km NNW of Federal Way, Washington
  8. 1.6 Puget Sound region, Washington
  9. 2.1 Puget Sound region, Washington
  10. 1.5 Puget Sound region, Washington
  11. 1.8 4 km S of Seabeck, Washington
  12. 1.7 Puget Sound region, Washington
  13. 2.1 14 km N of Hoodsport, Washington
  14. 1.7 Puget Sound region, Washington
  15. 1.5 3 km SSE of Quilcene, 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.