QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Seattle, WA

No earthquake was likely felt in Seattle in the 24 hours to 5:47 am PST (13:47 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 1.5 earthquake was recorded 40 km (25 mi) west-southwest of Seattle, WA, at 6:33 pm PDT on 30 August 2023 (01:33 UTC), 22 km deep.

USGS: Puget Sound region, Washington

39 km (24 mi) WSW of Seattle, WA · 37 km (23 mi) W of Burien, WA

6:33 pm PDT, Aug 30, 2023 · · 22 km deep · released about 5.6 lb of TNT

Every earthquake near Seattle Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Kitsap County 21 kmMason County 30 kmJefferson County 61 kmThurston County 63 kmPierce County 72 kmIsland County 74 kmKing County 76 kmGrays Harbor County 86 kmSnohomish 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
6:33 pm PDT on 30 August 2023 ()
Where
40 km (25 mi) west-southwest of Seattle, WA · earthquakes near Seattle
Magnitude
M 1.5 (ml)
Depth
22 km below the surface
Felt
no reports yet
Nearest
Kitsap County, 21 km NE
Nearest mapped fault
Seattle 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 1169 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, 40 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: Belfair, Allyn, Navy Yard City, Erlands Point-Kitsap Lake, Seabeck, Chico.

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

The largest earthquake within 50 km since 2016 was M 4.1 on 2017-02-23 — about 7,400 times the energy of this one.

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 · 40 km SSE of this epicentre
  2. 6.7 1 km ENE of Dash Point, Washington · 38 km ESE of this epicentre
  3. 6.1 Puget Sound region, Washington · 13 km SSE of this epicentre
  4. 5.8 Puget Sound area, Washington · 25 km S of this epicentre
  5. 5.3 Eastern Olympic Peninsula, Washington · 35 km NNW 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 47.5025, -122.8420. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Kitsap County, WA 21 km (13 mi) NE earthquakes near Kitsap County
Mason County, WA 30 km (19 mi) SW earthquakes near Mason County
Jefferson County, WA 61 km (38 mi) WNW earthquakes near Jefferson County
Thurston County, WA 63 km (39 mi) S earthquakes near Thurston County
Pierce County, WA 72 km (45 mi) SE earthquakes near Pierce County
Island County, WA 74 km (46 mi) N earthquakes near Island County

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

Aftershocks so far

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

  1. 1.7 10 km S of Seabeck, Washington
  2. 2.6 7 km WNW of Lofall, Washington
  3. 2.3 0 km ESE of Waller, Washington
  4. 1.9 6 km ENE of Lofall, Washington
  5. 2.2 8 km ENE of Quilcene, Washington
  6. 1.9 5 km WSW of Shelton, Washington
  7. 1.5 5 km S of Shelton, Washington
  8. 1.6 3 km WNW of Shoreline, Washington
  9. 1.9 8 km WNW of Shelton, Washington
  10. 2.0 2 km ESE of Ruston, Washington
  11. 1.7 22 km WSW of Quilcene, Washington
  12. 1.6 13 km WNW of Belfair, Washington
  13. 1.6 10 km S of Shelton, Washington
  14. 1.7 5 km SW of Port Ludlow, Washington
  15. 1.5 6 km SE of Maplewood, 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.