QuakeIndex

Earthquake · reviewed by a seismologist

M 3.0ml

Earthquake near Big Lake, WA

No earthquake was likely felt in Big Lake in the 24 hours to 2:17 am PST (10:17 UTC). The last one was M 2.6, 5 km (3 mi) WNW, at 9:17 pm PDT on 11 September 2026, estimated intensity II (weak) in town; 10 felt reports to USGS. Every earthquake near Big Lake

This page: a magnitude 3.0 earthquake was recorded 3 km (2 mi) east-southeast of Big Lake, WA, at 2:11 pm PST on 9 November 2021 (22:11 UTC), 16 km deep. 54 people have reported feeling it to USGS.

USGS: 2 km ESE of Big Lake, Washington

87 km (54 mi) N of Seattle, WA · 35 km (22 mi) N of Marysville, WA

2:11 pm PST, Nov 9, 2021 · · 16 km deep · released about 950 lb of TNT

Every earthquake near Big Lake Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Skagit County 31 kmIsland County 44 kmSnohomish County 50 kmWhatcom County 56 kmSan Juan County 67 kmKitsap County 90 kmKing County 105 kmJefferson County 118 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
2:11 pm PST on 9 November 2021 ()
Where
3 km (2 mi) east-southeast of Big Lake, WA · earthquakes near Big Lake
Magnitude
M 3.0 (ml)
Depth
16 km below the surface
Felt
54 reports · strongest reported intensity III
Measured shaking
intensity III (ShakeMap)
Nearest
Skagit County, 31 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1763 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 33 km (21 mi) from the epicentre. In Big Lake, 3 km away, the estimate is intensity III (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: Mount Vernon 10 km, intensity II · Sedro-Woolley 12 km, intensity II · Arlington 23 km, intensity II · Anacortes 33 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 950 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 350,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 16,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 11,000× the energy of this one
  4. This earthquake M 3.0 about 950 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:

  1. 5.0 4 km ENE of Machias, Washington · 47 km SSE of this epicentre
  2. 5.0 6 km W of Conway, Washington · 18 km WSW of this epicentre
  3. 5.0 4 km ENE of Deming, Washington · 50 km N 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 48.3970, -122.2045. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Skagit County, WA 31 km (19 mi) ENE earthquakes near Skagit County
Island County, WA 44 km (27 mi) SW earthquakes near Island County
Snohomish County, WA 50 km (31 mi) SE earthquakes near Snohomish County
Whatcom County, WA 56 km (35 mi) NNE earthquakes near Whatcom County
San Juan County, WA 67 km (42 mi) W earthquakes near San Juan County
Kitsap County, WA 90 km (56 mi) SSW earthquakes near Kitsap County

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

Aftershocks so far

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

  1. 1.9 1 km ENE of Granite Falls, Washington
  2. 1.6 14 km NNE of Hamilton, Washington
  3. 1.8 2 km SW of Deming, Washington
  4. 1.9 4 km ENE of La Conner, Washington
  5. 1.7 1 km ENE of Granite Falls, Washington
  6. 1.6 7 km SSE of Concrete, Washington
  7. 1.7 1 km E of Granite Falls, Washington
  8. 1.6 2 km E of Granite Falls, Washington
  9. 1.8 2 km E of Granite Falls, Washington
  10. 1.9 5 km S of Acme, Washington
  11. 1.6 2 km E of Granite Falls, Washington
  12. 1.7 4 km NE of La Conner, Washington
  13. 1.7 Washington
  14. 1.6 4 km NE of Granite Falls, Washington
  15. 2.1 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.