QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9ml

Earthquake near Blaine, WA

No earthquake was likely felt in Blaine in the 24 hours to 9:44 am PST (17:44 UTC). The last one was M 4.5, 43 km (27 mi) S, at 5:02 am PST on 3 March 2025, estimated intensity III (weak) in town; 11,411 felt reports to USGS. Every earthquake near Blaine

This page: a magnitude 1.9 earthquake was recorded 5 km (3 mi) southwest of Blaine, WA, at 2:07 pm PDT on 30 September 2020 (21:07 UTC), 23 km deep.

USGS: 5 km SW of Blaine, Washington

34 km (21 mi) NW of Bellingham, WA · 120 km (75 mi) NNW of Everett, WA

2:07 pm PDT, Sep 30, 2020 · · 23 km deep · released about 21 lb of TNT

10 km30 km60 km120 km N San Juan County 56 kmWhatcom County 72 kmSkagit County 89 kmIsland County 90 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
2:07 pm PDT on 30 September 2020 ()
Where
5 km (3 mi) southwest of Blaine, WA · earthquakes near Blaine
Magnitude
M 1.9 (ml)
Depth
23 km below the surface
Felt
no reports yet
Nearest
San Juan County, 56 km SSW
Nearest mapped fault
Birch Bay fault, 4 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 2234 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 Blaine, 5 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: Birch Bay, Point Roberts, Ferndale, Lynden, Marietta, Marietta-Alderwood.

How big was it?

This earthquake released about 21 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 730,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 520,000× the energy of this one
  3. Around the size people start to feel M 3.0 46× the energy of this one
  4. This earthquake M 1.9 about 21 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 · 30 km S of this epicentre
  2. 5.5 21 km SSE of Point Roberts, Washington · 24 km SW of this epicentre
  3. 5.1 10 km ESE of Salt Spring Island, Canada · 45 km WSW of this epicentre
  4. 5.0 4 km ENE of Deming, Washington · 49 km ESE 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 48.9668, -122.8025. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Juan County, WA 56 km (35 mi) SSW earthquakes near San Juan County
Whatcom County, WA 72 km (45 mi) E earthquakes near Whatcom County
Skagit County, WA 89 km (56 mi) SE earthquakes near Skagit County
Island County, WA 90 km (56 mi) S earthquakes near Island County
Clallam County, WA 124 km (77 mi) SW earthquakes near Clallam County
Snohomish County, WA 127 km (79 mi) SE earthquakes near Snohomish 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. 2.5 14 km W of Marietta, Washington
  2. 2.1 5 km SW of Aldergrove, Canada
  3. 1.7 5 km WSW of Aldergrove, Canada
  4. 1.5 Washington
  5. 1.6 8 km WNW of Friday Harbor, Washington
  6. 1.8 9 km NW of Friday Harbor, Washington
  7. 2.3 6 km WNW of Orcas, Washington
  8. 1.6 6 km W of Orcas, Washington
  9. 2.7 6 km WNW of Orcas, Washington
  10. 2.1 7 km SSW of Birch Bay, Washington
  11. 1.5 0 km WNW of Sumas, Washington
  12. 1.6 11 km E of North Saanich, Canada
  13. 1.6 9 km NW of Orcas, Washington
  14. 2.2 8 km NE of Marietta-Alderwood, Washington
  15. 1.9 3 km SE of Surrey, Canada

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.