QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9ml

7 km ENE of Marrowstone, Washington

· 54 km deep · released about 780 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Island County 11 kmKitsap County 48 kmSan Juan County 61 kmSnohomish County 62 kmSkagit County 74 kmJefferson County 75 kmKing County 86 kmMason County 91 kmClallam County 96 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
Magnitude
M 2.9 (ml)
Depth
54 km below the surface
Felt
71 reports · strongest reported intensity III
Measured shaking
intensity II (ShakeMap)
Nearest
Island County, 11 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 299 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 71 people have reported feeling it to USGS.

How big was it?

This earthquake released about 780 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 19,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 14,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.2× the energy of this one
  4. This earthquake M 2.9 about 780 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.

Where

Epicentre 48.0720, -122.5967. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Island County, WA 11 km (7 mi) SSE of here earthquakes near Island County
Kitsap County, WA 48 km (30 mi) N of here earthquakes near Kitsap County
San Juan County, WA 61 km (38 mi) SE of here earthquakes near San Juan County
Snohomish County, WA 62 km (38 mi) W of here earthquakes near Snohomish County
Skagit County, WA 74 km (46 mi) SW of here earthquakes near Skagit County
Jefferson County, WA 75 km (47 mi) ENE of here earthquakes near Jefferson 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. 2.3 5 km SE of Kingston, Washington
  2. 2.0 2 km E of Oak Harbor, Washington
  3. 2.3 2 km E of Oak Harbor, Washington
  4. 3.8 2 km E of Oak Harbor, Washington
  5. 2.4 2 km ESE of Oak Harbor, Washington
  6. 1.6 4 km S of Port Ludlow, Washington
  7. 1.5 2 km E of Oak Harbor, Washington
  8. 2.0 2 km ESE of Oak Harbor, Washington
  9. 1.6 2 km ESE of Oak Harbor, Washington
  10. 2.4 2 km ESE of Oak Harbor, Washington
  11. 2.9 2 km ESE of Oak Harbor, Washington
  12. 1.6 6 km SSW of Port Ludlow, Washington
  13. 2.4 4 km SSW of Anacortes, Washington
  14. 1.5 1 km E of Edmonds, Washington
  15. 1.5 2 km WNW of Arlington, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.3 on 2023-10-09 — it released about 110 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.