QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Seattle, WA

No earthquake was likely felt in Seattle in the 24 hours to 8:48 am PST (16:48 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

This page: a magnitude 1.8 earthquake was recorded 38 km (24 mi) north of Seattle, WA, at 4:15 pm PST on 21 November 2018 (00:15 UTC), 28 km deep.

USGS: 4 km SW of Clinton, Washington

37 km (23 mi) N of Seattle, WA · 16 km (10 mi) W of Everett, WA

4:15 pm PST, Nov 21, 2018 · · 28 km deep · released about 14 lb of TNT

Every earthquake near Seattle Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Island County 31 kmKitsap County 39 kmSnohomish County 49 kmKing County 66 kmSkagit County 75 kmSan Juan County 81 kmJefferson County 85 kmMason County 88 kmPierce County 101 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
4:15 pm PST on 21 November 2018 ()
Where
38 km (24 mi) north of Seattle, WA · earthquakes near Seattle
Magnitude
M 1.8 (ml)
Depth
28 km below the surface
Felt
no reports yet
Nearest
Island County, 31 km NW
Nearest mapped fault
Southern Whidbey Island fault, 1 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 2910 days ago

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

At this magnitude and depth it was probably too small to be felt, even directly above it. In Seattle, 38 km away, the estimate is intensity I (not felt). 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: Mukilteo, Picnic Point, Langley, Freeland, Hansville, Tulalip Bay.

How big was it?

This earthquake released about 14 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 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 790,000× the energy of this one
  3. Around the size people start to feel M 3.0 70× the energy of this one
  4. This earthquake M 1.8 about 14 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 5 earthquakes of M5 or more within 50 km:

  1. 5.4 8 km NNE of Lake Marcel-Stillwater, Washington · 45 km ESE of this epicentre
  2. 5.3 Eastern Olympic Peninsula, Washington · 47 km WSW of this epicentre
  3. 5.2 9 km NE of Lake Marcel-Stillwater, Washington · 48 km ESE of this epicentre
  4. 5.0 4 km ENE of Machias, Washington · 31 km E of this epicentre
  5. 5.0 6 km W of Conway, Washington · 43 km N 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 47.9483, -122.4040. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Island County, WA 31 km (19 mi) NW earthquakes near Island County
Kitsap County, WA 39 km (24 mi) SSW earthquakes near Kitsap County
Snohomish County, WA 49 km (30 mi) ENE earthquakes near Snohomish County
King County, WA 66 km (41 mi) SE earthquakes near King County
Skagit County, WA 75 km (46 mi) NE earthquakes near Skagit County
San Juan County, WA 81 km (50 mi) NW earthquakes near San Juan 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. 2.0 4 km E of Cathcart, Washington
  2. 1.8 3 km SSW of Roosevelt, Washington
  3. 1.7 3 km SSW of Roosevelt, Washington
  4. 1.8 4 km SSW of Roosevelt, Washington
  5. 3.5 3 km SSW of Roosevelt, Washington
  6. 4.6 2 km S of Roosevelt, Washington
  7. 2.0 3 km ENE of Granite Falls, Washington
  8. 2.1 4 km ENE of Lake Marcel-Stillwater, Washington
  9. 1.7 3 km SSW of Big Lake, Washington
  10. 1.6 5 km NNE of Kingston, Washington
  11. 1.5 4 km E of Riverside, Washington
  12. 1.9 3 km E of Granite Falls, Washington
  13. 2.6 3 km WSW of Erlands Point-Kitsap Lake, Washington
  14. 1.6 3 km ENE of Granite Falls, Washington
  15. 2.3 4 km N of Port Townsend, 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.