QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4ml

Earthquake near Monroe North, WA

No earthquake was likely felt in Monroe North in the 24 hours to 7:19 pm PST (03:19 UTC). The last one was M 4.2, 77 km (48 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 North

This page: a magnitude 2.4 earthquake was recorded 3 km (2 mi) northeast of Monroe North, WA, at 2:13 am PDT on 21 July 2017 (09:13 UTC), 17 km deep. 33 people have reported feeling it to USGS.

USGS: 2 km NE of Monroe North, Washington

42 km (26 mi) NE of Seattle, WA · 18 km (11 mi) ESE of Everett, WA

2:13 am PDT, Jul 21, 2017 · · 17 km deep · released about 120 lb of TNT

Every earthquake near Monroe North Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Snohomish County 23 kmKing County 46 kmKitsap County 59 kmIsland County 60 kmSkagit County 67 kmPierce County 95 kmChelan County 100 kmWhatcom County 105 kmSan Juan County 108 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
2:13 am PDT on 21 July 2017 ()
Where
3 km (2 mi) northeast of Monroe North, WA · earthquakes near Monroe North
Magnitude
M 2.4 (ml)
Depth
17 km below the surface
Felt
33 reports · strongest reported intensity III
Nearest
Snohomish County, 23 km NE
Nearest mapped fault
Southern Whidbey Island fault, 7 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 3318 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 12 km (7 mi) from the epicentre. In Monroe North, 3 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 5 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 120 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 130,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 92,000× the energy of this one
  3. Around the size people start to feel M 3.0 8.2× the energy of this one
  4. This earthquake M 2.4 about 120 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. 5.4 8 km NNE of Lake Marcel-Stillwater, Washington · 17 km SSE of this epicentre
  2. 5.2 9 km NE of Lake Marcel-Stillwater, Washington · 19 km SSE of this epicentre
  3. 5.0 4 km ENE of Machias, Washington · 12 km NNW 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 47.8985, -121.9633. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Snohomish County, WA 23 km (14 mi) NE earthquakes near Snohomish County
King County, WA 46 km (29 mi) SSE earthquakes near King County
Kitsap County, WA 59 km (37 mi) WSW earthquakes near Kitsap County
Island County, WA 60 km (37 mi) WNW earthquakes near Island County
Skagit County, WA 67 km (42 mi) N earthquakes near Skagit County
Pierce County, WA 95 km (59 mi) S earthquakes near Pierce 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. 1.5 3 km NE of Granite Falls, Washington
  2. 1.7 3 km W of Redmond, Washington
  3. 1.9 3 km ENE of Granite Falls, Washington
  4. 1.6 3 km W of Redmond, Washington
  5. 1.7 3 km SE of Duvall, Washington
  6. 1.6 2 km S of West Lake Sammamish, Washington
  7. 1.9 5 km NE of Oso, Washington
  8. 2.7 4 km WSW of Mercer Island, Washington
  9. 1.8 1 km SSW of Esperance, Washington
  10. 1.9 3 km E of Granite Falls, Washington
  11. 2.3 2 km WNW of Redmond, Washington
  12. 1.7 2 km N of Mercer Island, Washington
  13. 2.5 0 km S of Esperance, Washington
  14. 1.9 7 km SSW of Clinton, Washington
  15. 1.6 1 km S 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.