QuakeIndex

explosion · reviewed by a seismologist

M 1.5ml

Earthquake near Sunnyslope, WA

USGS: 5 km NNE of Sunnyslope, Washington

8:05 pm PDT, Jul 31, 2017 · · -1.2 km deep · released about 5.6 lb of TNT

10 km30 km60 km120 km N Chelan County 46 kmKittitas County 52 kmDouglas County 52 kmGrant County 71 kmKing County 115 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
8:05 pm PDT on 31 July 2017 ()
Where
5 km (3 mi) NNE of Sunnyslope, WA · earthquakes near Sunnyslope
Magnitude
M 1.5 (ml)
Depth
-1.2 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Chelan County, 46 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3349 days ago

A magnitude 1.5 earthquake was recorded 5 km (3 mi) NNE of Sunnyslope, WA, at 8:05 pm PDT on 31 July 2017 (03:05 UTC). 1 person has reported feeling it to USGS. This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: West Wenatchee, East Wenatchee Bench, Wenatchee, East Wenatchee, Cashmere, South Wenatchee.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 5.6 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 2,700,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
  3. Around the size people start to feel M 3.0 170× the energy of this one
  4. This earthquake M 1.5 about 5.6 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 47.5125, -120.2990. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Chelan County, WA 46 km (28 mi) NNW earthquakes near Chelan County
Kittitas County, WA 52 km (32 mi) SSW earthquakes near Kittitas County
Douglas County, WA 52 km (32 mi) ENE earthquakes near Douglas County
Grant County, WA 71 km (44 mi) ESE earthquakes near Grant County
King County, WA 115 km (72 mi) W earthquakes near King County
Yakima County, WA 122 km (76 mi) SSW earthquakes near Yakima County

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

Aftershocks so far

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

  1. 1.7 8 km W of Entiat, Washington
  2. 1.6 6 km WNW of Entiat, Washington
  3. 1.5 7 km N of Waterville, Washington
  4. 2.0 12 km WSW of Entiat, Washington
  5. 1.8 10 km NNE of Entiat, Washington
  6. 1.5 5 km S of Entiat, Washington
  7. 1.8 13 km WNW of Granite Falls, Washington
  8. 1.5 6 km W of Entiat, Washington
  9. 2.1 9 km WNW of Entiat, Washington
  10. 1.8 11 km SSW of Cashmere, Washington
  11. 2.0 18 km W of Entiat, Washington
  12. 1.5 10 km WNW of Entiat, Washington
  13. 1.6 9 km WNW of Entiat, Washington
  14. 1.6 5 km SW of Chelan Falls, Washington
  15. 1.6 13 km NNW of Thorp, 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.