QuakeIndex

explosion · reviewed by a seismologist

M 1.8ml

Earthquake near Granite Falls, WA

No earthquake was likely felt in Granite Falls in the 24 hours to 7:25 pm PST (03:25 UTC). The last one was M 2.6, 3 km (2 mi) ENE, at 2:29 pm PDT on 30 October 2026, estimated intensity III (weak) in town. Every earthquake near Granite Falls

No: USGS classifies this as a explosion, not an earthquake. A magnitude 1.8 explosion was recorded 4 km (2 mi) east of Granite Falls, WA, at 4:42 pm PDT on 15 June 2017 (23:42 UTC), less than 1 km deep. 9 people have reported feeling it to USGS.

USGS: 3 km E of Granite Falls, Washington

61 km (38 mi) NNE of Seattle, WA · 17 km (11 mi) E of Marysville, WA

4:42 pm PDT, Jun 15, 2017 · · -0.8 km deep · released about 16 lb of TNT

10 km30 km60 km120 km N Snohomish County 12 kmSkagit County 46 kmIsland County 56 kmKing County 67 kmKitsap County 74 kmWhatcom County 84 kmSan Juan County 99 kmChelan County 100 kmPierce County 117 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
4:42 pm PDT on 15 June 2017 ()
Where
4 km (2 mi) east of Granite Falls, WA · earthquakes near Granite Falls
Magnitude
M 1.8 (ml)
Depth
-0.8 km below the surface
Felt
9 reports · strongest reported intensity IV
Nearest
Snohomish County, 12 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3434 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 Granite Falls, 4 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: Lake Stevens 13 km, intensity II. Estimated for each town centre; each link is that town's own record.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 16 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 970,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 680,000× the energy of this one
  3. Around the size people start to feel M 3.0 61× the energy of this one
  4. This earthquake M 1.8 about 16 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. 5.4 8 km NNE of Lake Marcel-Stillwater, Washington · 36 km S of this epicentre
  2. 5.2 9 km NE of Lake Marcel-Stillwater, Washington · 38 km S of this epicentre
  3. 5.0 4 km ENE of Machias, Washington · 11 km SSW of this epicentre
  4. 5.0 6 km W of Conway, Washington · 47 km NW 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 48.0877, -121.9213. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Snohomish County, WA 12 km (8 mi) ESE earthquakes near Snohomish County
Skagit County, WA 46 km (28 mi) N earthquakes near Skagit County
Island County, WA 56 km (35 mi) W earthquakes near Island County
King County, WA 67 km (41 mi) S earthquakes near King County
Kitsap County, WA 74 km (46 mi) SW earthquakes near Kitsap County
Whatcom County, WA 84 km (52 mi) N earthquakes near Whatcom County

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

Aftershocks so far

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

  1. 1.7 3 km W of Redmond, Washington
  2. 1.9 3 km ENE of Granite Falls, Washington
  3. 1.6 3 km W of Redmond, Washington
  4. 1.7 3 km SE of Duvall, Washington
  5. 1.9 5 km NE of Oso, Washington
  6. 1.8 1 km SSW of Esperance, Washington
  7. 1.9 3 km E of Granite Falls, Washington
  8. 2.3 2 km WNW of Redmond, Washington
  9. 2.5 0 km S of Esperance, Washington
  10. 1.5 6 km NNW of Swede Heaven, Washington
  11. 1.9 7 km SSW of Clinton, Washington
  12. 1.6 1 km S of Lake Marcel-Stillwater, Washington
  13. 1.8 4 km E of Granite Falls, Washington
  14. 2.3 6 km W of Lake Cavanaugh, Washington
  15. 1.7 1 km N of Lake Roesiger, 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.