QuakeIndex

Earthquake · reviewed by a seismologist

M 3.5ml

Earthquake near Monroe, WA

No earthquake was likely felt in Monroe in the 24 hours to 9:17 pm PST (05:17 UTC). The last one was M 4.2, 76 km (47 mi) SW, at 2:05 pm PDT on 29 September 2026, estimated intensity II (weak) in town; 9,329 felt reports to USGS. Every earthquake near Monroe

This page: a magnitude 3.5 earthquake was recorded 4 km (3 mi) west-northwest of Monroe, WA, at 2:53 am PDT on 12 July 2019 (09:53 UTC), 31 km deep. 2,925 people have reported feeling it to USGS.

USGS: 3 km SSW of Roosevelt, Washington

36 km (23 mi) NE of Seattle, WA · 16 km (10 mi) SE of Everett, WA

2:53 am PDT, Jul 12, 2019 · · 31 km deep · released about 2.3 tons of TNT

10 km30 km60 km120 km N Snohomish County 29 kmKing County 44 kmKitsap County 53 kmIsland County 58 kmSkagit County 72 kmPierce County 91 kmMason County 103 kmChelan County 105 kmSan Juan County 107 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
2:53 am PDT on 12 July 2019 ()
Where
4 km (3 mi) west-northwest of Monroe, WA · earthquakes near Monroe
Magnitude
M 3.5 (ml)
Depth
31 km below the surface
Felt
2,925 reports · strongest reported intensity V
Measured shaking
intensity III (ShakeMap)
Nearest
Snohomish County, 29 km NE
Nearest mapped fault
Southern Whidbey Island fault, under 1 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 2012 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 52 km (32 mi) from the epicentre. In Monroe, 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: Monroe 4 km, intensity II · North Creek 12 km, intensity II · Lake Stevens 17 km, intensity II · Bothell 17 km, intensity II · Everett 18 km, intensity II · Lynnwood 22 km, intensity II · Redmond 22 km, intensity II · Marysville 24 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 2.3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.5 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 75,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 3,300× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,400× the energy of this one
  4. This earthquake M 3.5 about 2.3 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 4.7× more

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 50 times the energy of this one.

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

  1. 5.4 8 km NNE of Lake Marcel-Stillwater, Washington · 16 km SE of this epicentre
  2. 5.2 9 km NE of Lake Marcel-Stillwater, Washington · 20 km SE of this epicentre
  3. 5.0 4 km ENE of Machias, Washington · 15 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 47.8645, -122.0290. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Snohomish County, WA 29 km (18 mi) NE earthquakes near Snohomish County
King County, WA 44 km (27 mi) SSE earthquakes near King County
Kitsap County, WA 53 km (33 mi) WSW earthquakes near Kitsap County
Island County, WA 58 km (36 mi) NW earthquakes near Island County
Skagit County, WA 72 km (45 mi) NNE earthquakes near Skagit County
Pierce County, WA 91 km (56 mi) S earthquakes near Pierce County

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

Aftershocks so far

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

  1. 1.7 6 km NE of Fall City, Washington
  2. 3.0 8 km ENE of Fall City, Washington
  3. 1.7 6 km NE of Fall City, Washington
  4. 3.4 9 km NNE of Snoqualmie, Washington
  5. 1.6 2 km E of Snohomish, Washington
  6. 1.9 3 km ENE of Granite Falls, Washington
  7. 1.8 5 km WSW of Darrington, Washington
  8. 2.7 0 km WSW of Klahanie, Washington
  9. 1.6 8 km S of Baring, Washington
  10. 1.8 1 km E of Snoqualmie, Washington
  11. 1.7 2 km ESE of Lake Marcel-Stillwater, Washington
  12. 1.8 6 km WSW of Clinton, Washington
  13. 2.6 6 km WSW of Clinton, Washington
  14. 2.2 8 km SW of Warm Beach, Washington
  15. 2.6 1 km NE of Lake Marcel-Stillwater, 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.