QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Shoreline, WA

No earthquake was likely felt in Shoreline in the 24 hours to 5:35 am PST (13:35 UTC). The last one was M 4.2, 49 km (30 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 Shoreline

This page: a magnitude 1.5 earthquake was recorded 44 km (28 mi) west-northwest of Shoreline, WA, at 3:14 pm PDT on 23 April 2018 (22:14 UTC), 16 km deep.

USGS: 10 km N of Quilcene, Washington

52 km (32 mi) NW of Seattle, WA · 44 km (27 mi) WNW of Shoreline, WA

3:14 pm PDT, Apr 23, 2018 · · 16 km deep · released about 5.9 lb of TNT

10 km30 km60 km120 km N Island County 31 kmKitsap County 35 kmJefferson County 49 kmMason County 66 kmSan Juan County 68 kmClallam County 78 kmSnohomish County 85 kmKing County 92 kmSkagit County 102 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
3:14 pm PDT on 23 April 2018 ()
Where
44 km (28 mi) west-northwest of Shoreline, WA · earthquakes near Shoreline
Magnitude
M 1.5 (ml)
Depth
16 km below the surface
Felt
no reports yet
Nearest
Island County, 31 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3126 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 Shoreline, 44 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: Port Hadlock-Irondale, Port Ludlow, Lofall, Port Townsend, Sequim, Hansville.

How big was it?

This earthquake released about 5.9 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 2,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,800,000× the energy of this one
  3. Around the size people start to feel M 3.0 160× the energy of this one
  4. This earthquake M 1.5 about 5.9 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 6,900 times the energy of this one.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.3 Eastern Olympic Peninsula, Washington · 15 km SSW 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 47.9152, -122.8857. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Island County, WA 31 km (20 mi) NNE earthquakes near Island County
Kitsap County, WA 35 km (22 mi) SSE earthquakes near Kitsap County
Jefferson County, WA 49 km (31 mi) WSW earthquakes near Jefferson County
Mason County, WA 66 km (41 mi) SSW earthquakes near Mason County
San Juan County, WA 68 km (42 mi) NNW earthquakes near San Juan County
Clallam County, WA 78 km (48 mi) WNW earthquakes near Clallam County

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

Aftershocks so far

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

  1. 1.6 11 km NW of Jamestown, Washington
  2. 2.3 1 km NNE of Enetai, Washington
  3. 2.3 1 km SSW of Clinton, Washington
  4. 1.7 8 km W of Ault Field, Washington
  5. 1.8 7 km ESE of Quilcene, Washington
  6. 2.8 8 km WNW of Carlsborg, WA
  7. 1.7 6 km W of Lofall, Washington
  8. 1.9 3 km SSE of Port Ludlow, Washington
  9. 1.6 2 km N of Port Townsend, Washington
  10. 2.3 15 km SW of River Road, Washington
  11. 2.1 10 km NNE of Quilcene, Washington
  12. 2.1 5 km SW of Clinton, Washington
  13. 2.1 4 km WSW of Seabeck, Washington
  14. 1.5 25 km SSW of River Road, Washington
  15. 1.6 8 km S of Seabeck, 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.