QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near Olympia, WA

USGS: 18 km N of Satsop, Washington

98 km (61 mi) WSW of Seattle, WA · 46 km (28 mi) WNW of Olympia, WA

4:56 pm PST, Dec 4, 2019 · · 39 km deep · released about 9.6 lb of TNT

Every earthquake near Olympia Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Grays Harbor County 27 kmMason County 30 kmThurston County 55 kmJefferson County 71 kmPacific County 72 kmKitsap County 81 kmWahkiakum County 97 kmPierce County 101 kmLewis County 106 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
4:56 pm PST on 4 December 2019 ()
Where
45 km (28 mi) WNW of Olympia, WA · earthquakes near Olympia
Magnitude
M 1.7 (ml)
Depth
39 km below the surface
Felt
no reports yet
Nearest
Grays Harbor County, 27 km WSW
Nearest mapped fault
Saddle Mountain faults, 15 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 2494 days ago

A magnitude 1.7 earthquake was recorded 45 km (28 mi) WNW of Olympia, WA, at 4:56 pm PST on 4 December 2019 (00:56 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: Elma, McCleary, Montesano, Central Park, Shelton.

How big was it?

This earthquake released about 9.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
  3. Around the size people start to feel M 3.0 99× the energy of this one
  4. This earthquake M 1.7 about 9.6 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

The largest earthquake within 50 km since 2016 was M 4.1 on 2017-02-23 — about 4,300 times the energy of this one.

Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:

  1. 5.8 Puget Sound area, Washington · 45 km ENE of this epicentre
  2. 5.8 8 km N of Satsop, Washington · 10 km S of this epicentre
  3. 5.1 Olympic Peninsula, Washington · 7 km NE of this epicentre
  4. 5.0 18 km N of Satsop, Washington · 2 km W 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 47.1663, -123.4715. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Grays Harbor County, WA 27 km (17 mi) WSW earthquakes near Grays Harbor County
Mason County, WA 30 km (19 mi) NE earthquakes near Mason County
Thurston County, WA 55 km (34 mi) ESE earthquakes near Thurston County
Jefferson County, WA 71 km (44 mi) N earthquakes near Jefferson County
Pacific County, WA 72 km (45 mi) SSW earthquakes near Pacific County
Kitsap County, WA 81 km (50 mi) NE earthquakes near Kitsap County

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

Aftershocks so far

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

  1. 1.8 4 km N of Humptulips, Washington
  2. 2.6 8 km NW of Hoquiam, Washington
  3. 1.8 Olympic Peninsula, Washington
  4. 2.1 14 km N of Hoodsport, Washington
  5. 1.7 2 km N of Oakville, Washington
  6. 1.7 5 km WSW of Neilton, Washington
  7. 1.9 5 km SSE of Cosmopolis, Washington
  8. 1.6 12 km ENE of McCleary, Washington
  9. 2.6 11 km WNW of Hoodsport, Washington
  10. 2.4 11 km NE of Hoodsport, Washington
  11. 1.6 11 km S of Shelton, Washington
  12. 1.5 4 km N of McCleary, Washington
  13. 1.7 4 km ENE of Elma, Washington
  14. 1.6 10 km ESE of Markham, Washington
  15. 1.7 27 km NW of Hoodsport, 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.