QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

28 km NNW of Winthrop, Washington

· 9.8 km deep · released about 5.9 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Okanogan County 47 kmChelan County 98 kmWhatcom County 112 kmSkagit County 112 kmDouglas County 119 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 1.5 (ml)
Depth
9.8 km below the surface
Felt
no reports yet
Nearest
Okanogan County, 47 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1504 days ago

A magnitude 1.5 earthquake was recorded 28 km NNW of Winthrop, Washington at 21:53 UTC on 2022-08-20. This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 5.9 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,800,000× the energy of this one
  3. Around the size people start to feel M 3.0 160× the energy of this one
  4. This earthquake M 1.5 about 5.9 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 since 1900 lists no earthquake of M5 or more within 50 km.

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 48.7213, -120.3255. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Okanogan County, WA 47 km (29 mi) ESE earthquakes near Okanogan County
Chelan County, WA 98 km (61 mi) SSW earthquakes near Chelan County
Whatcom County, WA 112 km (69 mi) W earthquakes near Whatcom County
Skagit County, WA 112 km (70 mi) WSW earthquakes near Skagit County
Douglas County, WA 119 km (74 mi) SSE earthquakes near Douglas County
Snohomish County, WA 130 km (81 mi) SW earthquakes near Snohomish County

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

Aftershocks so far

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

  1. 1.3 16 km NW of Conconully, Washington
  2. 1.6 13 km WSW of Winthrop, Washington
  3. 1.9 24 km N of Winthrop, Washington
  4. 1.6 27 km NNW of Winthrop, Washington
  5. 1.6 26 km NNW of Winthrop, Washington
  6. 2.0 25 km NNW of Winthrop, Washington
  7. 2.1 52 km SSW of Princeton, Canada
  8. 1.6 29 km WSW of Oliver, Canada
  9. 1.7 56 km S of Princeton, Canada
  10. 1.7 54 km S of Princeton, Canada
  11. 2.6 14 km E of Winthrop, Washington
  12. 1.7 45 km NW of Winthrop, Washington
  13. 1.6 27 km NW of Conconully, Washington
  14. 1.6 13 km NW of Conconully, Washington
  15. 1.7 14 km NW of Conconully, 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.