QuakeIndex

explosion · reviewed by a seismologist

M 1.7ml

Earthquake near Sequim, WA

No earthquake was likely felt in Sequim in the 24 hours to 3:44 pm PST (23:44 UTC). The last one was M 4.2, 81 km (50 mi) SSE, at 2:05 pm PDT on 29 September 2026, estimated intensity II (weak) in town; 9,329 felt reports to USGS. Every earthquake near Sequim

No: USGS classifies this as a explosion, not an earthquake. A magnitude 1.7 explosion was recorded 4 km (3 mi) south-southwest of Sequim, WA, at 3:29 pm PDT on 15 April 2026 (22:29 UTC), less than 1 km deep.

USGS: 2 km S of River Road, Washington

75 km (47 mi) NW of Seattle, WA

3:29 pm PDT, Apr 15, 2026 · · -0.5 km deep · released about 12 lb of TNT

10 km30 km60 km120 km N Island County 36 kmJefferson County 40 kmSan Juan County 52 kmClallam County 57 kmKitsap County 58 kmMason County 77 kmSnohomish County 102 kmSkagit County 109 kmKing County 115 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
3:29 pm PDT on 15 April 2026 ()
Where
4 km (3 mi) south-southwest of Sequim, WA · earthquakes near Sequim
Magnitude
M 1.7 (ml)
Depth
-0.5 km below the surface
Felt
no reports yet
Nearest
Island County, 36 km ENE
Nearest mapped fault
Lake Creek-Boundary Creek fault, 12 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 210 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 13 km (8 mi) from the epicentre. In Sequim, 4 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: Sequim 4 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 12 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 870,000× the energy of this one
  3. Around the size people start to feel M 3.0 78× the energy of this one
  4. This earthquake M 1.7 about 12 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 4.3 on 2023-10-09 — about 7,200 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 · 29 km SSE 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 48.0443, -123.1310. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Island County, WA 36 km (23 mi) ENE earthquakes near Island County
Jefferson County, WA 40 km (25 mi) SW earthquakes near Jefferson County
San Juan County, WA 52 km (32 mi) N earthquakes near San Juan County
Clallam County, WA 57 km (35 mi) W earthquakes near Clallam County
Kitsap County, WA 58 km (36 mi) SE earthquakes near Kitsap County
Mason County, WA 77 km (48 mi) S earthquakes near Mason County

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

Aftershocks so far

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

  1. 1.4 8 km SW of Camano, Washington
  2. 0.6 6 km ESE of Quilcene, Washington
  3. 0.9 5 km NNW of Bangor Trident Base, Washington
  4. 1.1 7 km NNW of Bangor Trident Base, Washington
  5. 0.5 3 km ESE of Quilcene, Washington
  6. 0.7 7 km NNE of Brinnon, Washington
  7. 0.2 6 km E of Quilcene, Washington
  8. 0.4 6 km ENE of Oak Bay, Canada
  9. 0.1 7 km NNE of Brinnon, Washington
  10. 1.7 8 km SSE of Oak Bay, Canada
  11. 1.0 34 km SSW of Port Angeles, Washington
  12. 1.2 5 km SSW of Port Ludlow, Washington
  13. 2.1 6 km ENE of Bell Hill, Washington
  14. 1.6 2 km ESE of Oak Harbor, Washington
  15. 1.6 8 km S of Port Hadlock-Irondale, 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.