QuakeIndex

explosion · reviewed by a seismologist

M 1.6ml

Earthquake near Bethel, WA

No earthquake was likely felt in Bethel in the 24 hours to 4:34 am PST (12:34 UTC). The last one was M 4.2, 12 km (8 mi) SSW, at 2:05 pm PDT on 29 September 2026, estimated intensity III (weak) in town; 9,329 felt reports to USGS. Every earthquake near Bethel

No: USGS classifies this as a explosion, not an earthquake. A magnitude 1.6 explosion was recorded 4 km (2 mi) south-southwest of Bethel, WA, at 4:07 pm PDT on 16 September 2021 (23:07 UTC), less than 1 km deep.

USGS: 3 km SSW of Bethel, Washington

28 km (17 mi) SW of Seattle, WA · 23 km (14 mi) W of Burien, WA

4:07 pm PDT, Sep 16, 2021 · · -0.3 km deep · released about 7.6 lb of TNT

10 km30 km60 km120 km N Kitsap County 20 kmMason County 42 kmPierce County 59 kmThurston County 60 kmKing County 61 kmJefferson County 76 kmIsland County 77 kmSnohomish County 93 kmGrays Harbor County 97 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
4:07 pm PDT on 16 September 2021 ()
Where
4 km (2 mi) south-southwest of Bethel, WA · earthquakes near Bethel
Magnitude
M 1.6 (ml)
Depth
-0.3 km below the surface
Felt
no reports yet
Nearest
Kitsap County, 20 km N
Nearest mapped fault
Tacoma fault, 9 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 1884 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 11 km (7 mi) from the epicentre. In Bethel, 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.

Earthquakes near other towns within 30 km: Burley, East Port Orchard, Parkwood, Purdy, Port Orchard, Wauna.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 7.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.6 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 5,400 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 · 35 km S of this epicentre
  2. 6.7 1 km ENE of Dash Point, Washington · 23 km SE of this epicentre
  3. 6.1 Puget Sound region, Washington · 11 km SW of this epicentre
  4. 5.8 Puget Sound area, Washington · 28 km SW of this epicentre
  5. 5.3 Eastern Olympic Peninsula, Washington · 46 km NW 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 47.4628, -122.6440. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Kitsap County, WA 20 km (12 mi) N earthquakes near Kitsap County
Mason County, WA 42 km (26 mi) WSW earthquakes near Mason County
Pierce County, WA 59 km (37 mi) SE earthquakes near Pierce County
Thurston County, WA 60 km (37 mi) SSW earthquakes near Thurston County
King County, WA 61 km (38 mi) E earthquakes near King County
Jefferson County, WA 76 km (47 mi) WNW earthquakes near Jefferson County

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

Aftershocks so far

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

  1. 1.9 1 km SSW of Erlands Point-Kitsap Lake, Washington
  2. 2.2 8 km SSW of Grapeview, Washington
  3. 1.5 5 km SW of Des Moines, Washington
  4. 1.8 5 km SW of Des Moines, Washington
  5. 1.6 Puget Sound region, Washington
  6. 1.6 8 km WSW of Home, Washington
  7. 1.5 7 km WNW of Lofall, Washington
  8. 1.8 2 km SSE of Lake Forest Park, Washington
  9. 1.9 7 km SSW of Port Ludlow, Washington
  10. 1.9 7 km WNW of Lofall, Washington
  11. 2.3 5 km WNW of Wauna, Washington
  12. 1.5 8 km WNW of Lofall, Washington
  13. 3.7 7 km WNW of Lofall, Washington
  14. 1.5 5 km W of Gorst, Washington
  15. 1.5 3 km W of Hoodsport, 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.