QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Boulevard Park, WA

No earthquake was likely felt in Boulevard Park in the 24 hours to 2:09 am PST (10:09 UTC). The last one was M 4.2, 33 km (20 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 Boulevard Park

This page: a magnitude 1.5 earthquake was recorded in Boulevard Park, WA, at 10:47 am PDT on 6 August 2021 (17:47 UTC), 27 km deep.

USGS: 1 km N of Boulevard Park, Washington

14 km (9 mi) S of Seattle, WA · in Burien, WA

10:47 am PDT, Aug 6, 2021 · · 27 km deep · released about 6.2 lb of TNT

10 km30 km60 km120 km N Kitsap County 29 kmKing County 36 kmPierce County 51 kmMason County 66 kmThurston County 74 kmSnohomish County 74 kmIsland County 78 kmJefferson County 97 kmLewis 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
10:47 am PDT on 6 August 2021 ()
Where
in Boulevard Park, WA · earthquakes near Boulevard Park
Magnitude
M 1.5 (ml)
Depth
27 km below the surface
Felt
no reports yet
Nearest
Kitsap County, 29 km WNW
Nearest mapped fault
Seattle fault, 2 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 1925 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. 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: Riverton, White Center, Burien, Tukwila, Bryn Mawr-Skyway, SeaTac.

How big was it?

This earthquake released about 6.2 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 1,700,000× the energy of this one
  3. Around the size people start to feel M 3.0 150× the energy of this one
  4. This earthquake M 1.5 about 6.2 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 4.6 on 2019-07-12 — about 36,000 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 · 50 km SW of this epicentre
  2. 6.7 1 km ENE of Dash Point, Washington · 20 km SSW of this epicentre
  3. 6.1 Puget Sound region, Washington · 34 km WSW of this epicentre
  4. 5.4 8 km NNE of Lake Marcel-Stillwater, Washington · 44 km NE of this epicentre
  5. 5.2 9 km NE of Lake Marcel-Stillwater, Washington · 46 km NE 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 47.4983, -122.3173. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Kitsap County, WA 29 km (18 mi) WNW earthquakes near Kitsap County
King County, WA 36 km (23 mi) E earthquakes near King County
Pierce County, WA 51 km (32 mi) SSE earthquakes near Pierce County
Mason County, WA 66 km (41 mi) WSW earthquakes near Mason County
Thurston County, WA 74 km (46 mi) SSW earthquakes near Thurston County
Snohomish County, WA 74 km (46 mi) NNE earthquakes near Snohomish County

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

Aftershocks so far

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

  1. 2.4 7 km ENE of Fall City, Washington
  2. 2.0 7 km NE of Fall City, Washington
  3. 2.0 3 km SE of Issaquah, Washington
  4. 1.5 3 km NNE of Picnic Point, Washington
  5. 1.6 1 km SW of Bothell East, Washington
  6. 1.7 3 km WNW of Gorst, Washington
  7. 1.5 1 km WSW of Silverdale, Washington
  8. 1.8 1 km SW of Monroe North, Washington
  9. 1.5 2 km WNW of Gig Harbor, Washington
  10. 1.6 6 km SW of Des Moines, Washington
  11. 1.5 5 km NNE of Duvall, Washington
  12. 1.9 1 km ESE of Esperance, Washington
  13. 2.2 1 km NNE of Cathcart, Washington
  14. 1.5 10 km ESE of Enumclaw, Washington
  15. 1.6 7 km WNW of Gorst, 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.