QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Vashon, WA

No earthquake was likely felt in Vashon in the 24 hours to 8:45 am PST (16:45 UTC). The last one was M 4.2, 20 km (13 mi) WSW, at 2:05 pm PDT on 29 September 2026, estimated intensity III (weak) in town; 9,329 felt reports to USGS. Every earthquake near Vashon

This page: a magnitude 1.5 earthquake was recorded 5 km (3 mi) south-southeast of Vashon, WA, at 3:22 pm PST on 16 February 2018 (23:22 UTC), 20 km deep.

USGS: 4 km SSE of Vashon, Washington

24 km (15 mi) SSW of Seattle, WA · 9 km (6 mi) SW of Burien, WA

3:22 pm PST, Feb 16, 2018 · · 20 km deep · released about 5.6 lb of TNT

10 km30 km60 km120 km N Kitsap County 30 kmPierce County 45 kmKing County 45 kmMason County 57 kmThurston County 61 kmIsland County 85 kmSnohomish County 87 kmLewis County 93 kmJefferson County 93 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
3:22 pm PST on 16 February 2018 ()
Where
5 km (3 mi) south-southeast of Vashon, WA · earthquakes near Vashon
Magnitude
M 1.5 (ml)
Depth
20 km below the surface
Felt
no reports yet
Nearest
Kitsap County, 30 km NNW
Nearest mapped fault
Tacoma fault, 6 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 3191 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 Vashon, 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: Normandy Park, Des Moines, Burien, Maplewood, SeaTac, Southworth.

How big was it?

This earthquake released about 5.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,700,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
  3. Around the size people start to feel M 3.0 170× the energy of this one
  4. This earthquake M 1.5 about 5.6 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 6 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.8 The 2001 Nisqually, Washington Earthquake · 37 km SW of this epicentre
  2. 6.7 4 km WNW of Roy, Washington · 46 km SSW of this epicentre
  3. 6.7 1 km ENE of Dash Point, Washington · 10 km S of this epicentre
  4. 6.1 Puget Sound region, Washington · 25 km W of this epicentre
  5. 5.8 Puget Sound area, Washington · 39 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 47.4127, -122.4270. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Kitsap County, WA 30 km (19 mi) NNW earthquakes near Kitsap County
Pierce County, WA 45 km (28 mi) SSE earthquakes near Pierce County
King County, WA 45 km (28 mi) E earthquakes near King County
Mason County, WA 57 km (35 mi) W earthquakes near Mason County
Thurston County, WA 61 km (38 mi) SSW earthquakes near Thurston County
Island County, WA 85 km (53 mi) NNW earthquakes near Island County

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

Aftershocks so far

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

  1. 1.7 2 km SSE of Manchester, Washington
  2. 1.6 2 km SE of Manchester, Washington
  3. 1.6 2 km NE of Shoreline, Washington
  4. 2.8 2 km NNW of Fircrest, Washington
  5. 1.7 1 km SE of Keyport, Washington
  6. 1.5 3 km SSE of Des Moines, Washington
  7. 1.8 3 km S of Suquamish, Washington
  8. 1.6 4 km NE of Bainbridge Island, Washington
  9. 1.5 2 km ESE of Manchester, Washington
  10. 1.9 3 km E of Indianola, Washington
  11. 1.9 1 km SE of Dash Point, Washington
  12. 2.0 1 km SE of Keyport, Washington
  13. 1.6 1 km ENE of Enetai, Washington
  14. 1.7 2 km NNE of Southworth, Washington
  15. 1.5 8 km SW of Grapeview, 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.