QuakeIndex

explosion · reviewed by a seismologist

M 1.8ml

Earthquake near Lofall, WA

No earthquake was likely felt in Lofall in the 24 hours to 1:36 am PST (09:36 UTC). The last one was M 4.2, 46 km (29 mi) S, at 2:05 pm PDT on 29 September 2026, estimated intensity III (weak) in town; 9,329 felt reports to USGS. Every earthquake near Lofall

No: USGS classifies this as a explosion, not an earthquake. A magnitude 1.8 explosion was recorded 6 km (3 mi) north of Lofall, WA, at 11:29 am PST on 31 January 2022 (19:29 UTC), less than 1 km deep.

USGS: 5 km N of Lofall, Washington

36 km (22 mi) NW of Seattle, WA · 27 km (17 mi) WNW of Shoreline, WA

11:29 am PST, Jan 31, 2022 · · -0.3 km deep · released about 16 lb of TNT

10 km30 km60 km120 km N Kitsap County 25 kmIsland County 33 kmJefferson County 64 kmMason County 68 kmSnohomish County 71 kmKing County 75 kmSan Juan County 79 kmSkagit County 94 kmClallam County 95 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
11:29 am PST on 31 January 2022 ()
Where
6 km (3 mi) north of Lofall, WA · earthquakes near Lofall
Magnitude
M 1.8 (ml)
Depth
-0.3 km below the surface
Felt
no reports yet
Nearest
Kitsap County, 25 km S
Nearest mapped fault
Southern Whidbey Island fault, 14 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 1745 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 14 km (9 mi) from the epicentre. In Lofall, 6 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: Port Ludlow, Hansville, Poulsbo, Kingston, Bangor Trident Base, Indianola.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 16 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 930,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 660,000× the energy of this one
  3. Around the size people start to feel M 3.0 59× the energy of this one
  4. This earthquake M 1.8 about 16 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 one earthquake of M5 or more within 50 km:

  1. 5.3 Eastern Olympic Peninsula, Washington · 26 km WSW 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 47.8620, -122.6688. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Kitsap County, WA 25 km (15 mi) S earthquakes near Kitsap County
Island County, WA 33 km (20 mi) N earthquakes near Island County
Jefferson County, WA 64 km (40 mi) W earthquakes near Jefferson County
Mason County, WA 68 km (42 mi) SW earthquakes near Mason County
Snohomish County, WA 71 km (44 mi) ENE earthquakes near Snohomish County
King County, WA 75 km (47 mi) ESE earthquakes near King County

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

Aftershocks so far

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

  1. 1.6 5 km W of Burley, Washington
  2. 1.5 2 km SW of Gorst, Washington
  3. 1.9 1 km ENE of Enetai, Washington
  4. 1.6 0 km WSW of Esperance, Washington
  5. 1.6 1 km NNW of Keyport, Washington
  6. 1.9 0 km W of Keyport, Washington
  7. 1.6 5 km SSW of Port Ludlow, Washington
  8. 1.6 3 km N of Kingston, Washington
  9. 2.4 1 km SE of Manchester, Washington
  10. 1.7 6 km WNW of Gorst, Washington
  11. 1.6 Puget Sound region, Washington
  12. 1.5 4 km SSW of Clinton, Washington
  13. 1.7 4 km SW of White Center, Washington
  14. 1.8 3 km WSW of White Center, Washington
  15. 1.8 3 km NNW of Picnic Point, 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.