QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

Earthquake near Birch Bay, WA

No earthquake was likely felt in Birch Bay in the 24 hours to 12:33 pm PST (20:33 UTC). The last one was M 3.8, 71 km (44 mi) S, at 11:35 pm PDT on 1 July 2026, estimated intensity II (weak) in town; 2,030 felt reports to USGS. Every earthquake near Birch Bay

This page: a magnitude 2.1 earthquake was recorded 8 km (5 mi) south-southwest of Birch Bay, WA, at 4:46 pm PST on 20 February 2023 (00:46 UTC), 19 km deep. 1 person has reported feeling it to USGS.

USGS: 7 km SSW of Birch Bay, Washington

26 km (16 mi) WNW of Bellingham, WA · 141 km (88 mi) NNW of Seattle, WA

4:46 pm PST, Feb 20, 2023 · · 19 km deep · released about 44 lb of TNT

Every earthquake near Birch Bay Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Juan County 45 kmWhatcom County 69 kmIsland County 78 kmSkagit County 82 kmClallam County 116 kmSnohomish County 116 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
4:46 pm PST on 20 February 2023 ()
Where
8 km (5 mi) south-southwest of Birch Bay, WA · earthquakes near Birch Bay
Magnitude
M 2.1 (ml)
Depth
19 km below the surface
Felt
1 report · strongest reported intensity III
Nearest
San Juan County, 45 km SSW
Nearest mapped fault
Sandy Point fault, 3 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 1294 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 Birch Bay, 8 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: Ferndale, Blaine, Marietta, Marietta-Alderwood, Bellingham, Point Roberts.

How big was it?

This earthquake released about 44 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 5.8 340,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 240,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 44 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 4 earthquakes of M5 or more within 50 km:

  1. 6.0 San Juan Islands, Washington · 17 km S of this epicentre
  2. 5.5 21 km SSE of Point Roberts, Washington · 17 km WSW of this epicentre
  3. 5.1 10 km ESE of Salt Spring Island, Canada · 42 km W of this epicentre
  4. 5.0 4 km ENE of Deming, Washington · 46 km E 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 48.8538, -122.7833. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Juan County, WA 45 km (28 mi) SSW earthquakes near San Juan County
Whatcom County, WA 69 km (43 mi) E earthquakes near Whatcom County
Island County, WA 78 km (48 mi) S earthquakes near Island County
Skagit County, WA 82 km (51 mi) ESE earthquakes near Skagit County
Clallam County, WA 116 km (72 mi) SW earthquakes near Clallam County
Snohomish County, WA 116 km (72 mi) SE earthquakes near Snohomish County

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

Aftershocks so far

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

  1. 1.8 5 km SW of Custer, Washington
  2. 2.0 3 km S of Alger, Washington
  3. 1.5 8 km WNW of Orcas, Washington
  4. 2.3 3 km SE of Aldergrove East, Canada
  5. 1.5 10 km E of Orcas, Washington
  6. 4.5 2025 Orcas Island, Washington
  7. 1.5 11 km NNW of Orcas, Washington
  8. 1.8 2 km W of Point Roberts, Washington
  9. 2.1 3 km W of Point Roberts, Washington
  10. 1.7 2 km SW of Point Roberts, Washington
  11. 1.8 3 km WSW of Point Roberts, Washington
  12. 1.7 2 km WSW of Point Roberts, Washington
  13. 1.6 2 km W of Point Roberts, Washington
  14. 2.8 10 km WSW of Friday Harbor, Washington
  15. 1.9 6 km NNE of Orcas, 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.