QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

Earthquake near Tanner, WA

No earthquake was likely felt in Tanner in the 24 hours to 9:33 am PST (17:33 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 2.1 earthquake was recorded 11 km (7 mi) north-northeast of Tanner, WA, at 1:47 pm PST on 21 February 2021 (21:47 UTC), 9.1 km deep. 10 people have reported feeling it to USGS.

USGS: 11 km NNE of Tanner, Washington

51 km (32 mi) E of Seattle, WA · 27 km (17 mi) E of Sammamish, WA

1:47 pm PST, Feb 21, 2021 · · 9.1 km deep · released about 37 lb of TNT

10 km30 km60 km120 km N King County 14 kmSnohomish County 55 kmPierce County 67 kmKitsap County 73 kmChelan County 86 kmKittitas County 90 kmIsland County 99 kmSkagit County 104 kmThurston County 112 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
1:47 pm PST on 21 February 2021 ()
Where
11 km (7 mi) north-northeast of Tanner, WA · earthquakes near Tanner
Magnitude
M 2.1 (ml)
Depth
9.1 km below the surface
Felt
10 reports · strongest reported intensity III
Nearest
King County, 14 km SW
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 2019 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 14 km (9 mi) from the epicentre. In Tanner, 11 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: Snoqualmie 12 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 37 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 410,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 290,000× the energy of this one
  3. Around the size people start to feel M 3.0 26× the energy of this one
  4. This earthquake M 2.1 about 37 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 6,000 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 · 27 km NW of this epicentre
  2. 5.2 9 km NE of Lake Marcel-Stillwater, Washington · 24 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 47.5640, -121.6760. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
King County, WA 14 km (9 mi) SW earthquakes near King County
Snohomish County, WA 55 km (34 mi) N earthquakes near Snohomish County
Pierce County, WA 67 km (42 mi) SSW earthquakes near Pierce County
Kitsap County, WA 73 km (46 mi) W earthquakes near Kitsap County
Chelan County, WA 86 km (53 mi) ENE earthquakes near Chelan County
Kittitas County, WA 90 km (56 mi) ESE earthquakes near Kittitas County

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

Aftershocks so far

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

  1. 1.7 12 km W of Greenwater, Washington
  2. 1.5 5 km NNE of Duvall, Washington
  3. 2.2 1 km NNE of Cathcart, Washington
  4. 1.5 10 km ESE of Enumclaw, Washington
  5. 1.8 14 km S of Gold Bar, Washington
  6. 1.5 1 km E of Ames Lake, Washington
  7. 1.5 11 km ESE of Enumclaw, Washington
  8. 1.7 6 km NE of Snoqualmie, Washington
  9. 1.7 5 km SW of Fall City, Washington
  10. 1.7 3 km E of Carnation, Washington
  11. 1.6 3 km S of Monroe, Washington
  12. 1.6 8 km NE of Tanner, Washington
  13. 1.8 2 km NE of Mirrormont, Washington
  14. 1.5 1 km SSW of Ravensdale, Washington
  15. 2.2 9 km NNE of Snoqualmie, 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.