Earthquake · reviewed by a seismologist
M 1.8ml
Earthquake near Sedro-Woolley, WA
No earthquake was likely felt in Sedro-Woolley in the 24 hours to 11:53 pm PST (07:53 UTC). The last one was M 2.6, 10 km (6 mi) SSW, at 9:17 pm PDT on 11 September 2026, estimated intensity II (weak) in town; 10 felt reports to USGS. Every earthquake near Sedro-Woolley
This page: a magnitude 1.8 earthquake was recorded 50 km (31 mi) east of Sedro-Woolley, WA, at 1:44 am PDT on 13 August 2024 (08:44 UTC), 4.9 km deep.
USGS: 9 km NNE of Rockport, Washington
- When
- 1:44 am PDT on 13 August 2024 ()
- Where
- 50 km (31 mi) east of Sedro-Woolley, WA · earthquakes near Sedro-Woolley
- Magnitude
- M 1.8 (ml)
- Depth
- 4.9 km below the surface
- Felt
- no reports yet
- Nearest
- Skagit County, 20 km WSW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 822 days ago
Earthquake alerts for Sedro-Woolley, WA
Get a notification in this browser when USGS records an earthquake near Sedro-Woolley, WA. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
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 13 km (8 mi) from the epicentre. In Sedro-Woolley, 50 km away, the estimate is intensity I (not felt). 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.
How big was it?
This earthquake released about 15 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.
- Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
- Magna, Utah 2020 M 5.7 710,000× the energy of this one
- Around the size people start to feel M 3.0 63× the energy of this one
- This earthquake M 1.8 about 15 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 one earthquake of M5 or more within 50 km:
- 5.6 Near Marblemount, Washington · 14 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 48.5642, -121.5675. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Skagit County, WA | 20 km (12 mi) | WSW | earthquakes near Skagit County |
| Whatcom County, WA | 37 km (23 mi) | NNW | earthquakes near Whatcom County |
| Snohomish County, WA | 58 km (36 mi) | SSW | earthquakes near Snohomish County |
| Island County, WA | 93 km (58 mi) | WSW | earthquakes near Island County |
| Chelan County, WA | 105 km (65 mi) | SE | earthquakes near Chelan County |
| San Juan County, WA | 113 km (70 mi) | W | earthquakes near San Juan County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
39 earthquakes have been recorded within 50 km since this one.
- 1.0 8 km NW of Swede Heaven, Washington
- 1.0 5 km SW of Darrington, Washington
- 0.9 3 km ENE of Swede Heaven, Washington
- 2.3 22 km ESE of Darrington, Washington
- 1.1 11 km N of Concrete, Washington
- 0.9 2 km WNW of Lyman, Washington
- 1.1 3 km NNE of Lyman, Washington
- 1.1 6 km NE of Oso, Washington
- 0.7 6 km SSE of Concrete, Washington
- 1.6 3 km WSW of Lake Cavanaugh, Washington
- 1.8 15 km ESE of Acme, Washington
- 1.9 7 km SSE of Concrete, Washington
- 1.9 2 km NNE of Lyman, Washington
- 1.7 3 km N of Lyman, Washington
- 2.2 2 km N of Lyman, 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.