QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

Earthquake near Tanner, WA

No earthquake was likely felt in Tanner in the 24 hours to 9:32 am PST (17:32 UTC). The last one was M 2.6, 9 km (6 mi) SW, at 6:09 pm PDT on 14 October 2026, estimated intensity II (weak) in town; 46 felt reports to USGS. Every earthquake near Tanner

This page: a magnitude 1.6 earthquake was recorded 9 km (6 mi) northeast of Tanner, WA, at 6:23 pm PST on 28 November 2021 (02:23 UTC), 15 km deep.

USGS: 8 km NE of Tanner, Washington

52 km (32 mi) E of Seattle, WA · 28 km (18 mi) ESE of Sammamish, WA

6:23 pm PST, Nov 28, 2021 · · 15 km deep · released about 6.6 lb of TNT

10 km30 km60 km120 km N King County 13 kmSnohomish County 58 kmPierce County 65 kmKitsap County 74 kmChelan County 87 kmKittitas County 88 kmIsland County 102 kmSkagit County 107 kmThurston County 110 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
6:23 pm PST on 28 November 2021 ()
Where
9 km (6 mi) northeast of Tanner, WA · earthquakes near Tanner
Magnitude
M 1.6 (ml)
Depth
15 km below the surface
Felt
no reports yet
Nearest
King County, 13 km WSW
Nearest mapped fault
Rattlesnake Mountain 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 1806 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 Tanner, 9 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: Riverbend, North Bend, Snoqualmie, Wilderness Rim, Fall City, Carnation.

How big was it?

This earthquake released about 6.6 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 2,300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,600,000× the energy of this one
  3. Around the size people start to feel M 3.0 140× the energy of this one
  4. This earthquake M 1.6 about 6.6 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 4.6 on 2019-07-12 — about 34,000 times the energy of this one.

Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:

  1. 5.4 8 km NNE of Lake Marcel-Stillwater, Washington · 29 km NNW of this epicentre
  2. 5.2 9 km NE of Lake Marcel-Stillwater, Washington · 27 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 47.5365, -121.6698. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
King County, WA 13 km (8 mi) WSW earthquakes near King County
Snohomish County, WA 58 km (36 mi) N earthquakes near Snohomish County
Pierce County, WA 65 km (40 mi) SW earthquakes near Pierce County
Kitsap County, WA 74 km (46 mi) W earthquakes near Kitsap County
Chelan County, WA 87 km (54 mi) ENE earthquakes near Chelan County
Kittitas County, WA 88 km (55 mi) ESE earthquakes near Kittitas 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 ESE of Enumclaw, Washington
  2. 2.7 1 km NW of Maple Valley, Washington
  3. 1.7 6 km ESE of Tanner, Washington
  4. 1.8 1 km ESE of Union Hill-Novelty Hill, Washington
  5. 1.6 0 km NNE of Lake Marcel-Stillwater, Washington
  6. 1.6 Puget Sound region, Washington
  7. 1.6 0 km N of Lake Marcel-Stillwater, Washington
  8. 1.6 11 km W of Greenwater, Washington
  9. 2.3 3 km W of Hobart, Washington
  10. 2.8 2 km SW of Wilderness Rim, Washington
  11. 1.7 8 km ENE of Snoqualmie, Washington
  12. 1.7 Puget Sound region, Washington
  13. 1.6 2 km ESE of Wilderness Rim, Washington
  14. 1.5 12 km ESE of Riverbend, Washington
  15. 1.6 2 km NNE of Woods Creek, 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.