QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

Earthquake near Tacoma, WA

No earthquake was likely felt in Tacoma in the 24 hours to 9:49 am PST (17:49 UTC). The last one was M 4.2, 27 km (17 mi) NW, at 2:05 pm PDT on 29 September 2026, estimated intensity III (weak) in town; 9,329 felt reports to USGS. Every earthquake near Tacoma

This page: a magnitude 2.1 earthquake was recorded 30 km (19 mi) west-northwest of Tacoma, WA, at 9:35 am PST on 17 January 2020 (17:35 UTC), 45 km deep.

USGS: 2 km S of Grapeview, Washington

50 km (31 mi) SW of Seattle, WA · 28 km (18 mi) NW of Lakewood, WA

9:35 am PST, Jan 17, 2020 · · 45 km deep · released about 47 lb of TNT

Every earthquake near Tacoma Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mason County 26 kmKitsap County 39 kmThurston County 41 kmPierce County 59 kmJefferson County 76 kmGrays Harbor County 78 kmKing County 78 kmLewis County 88 kmIsland County 95 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
9:35 am PST on 17 January 2020 ()
Where
30 km (19 mi) west-northwest of Tacoma, WA · earthquakes near Tacoma
Magnitude
M 2.1 (ml)
Depth
45 km below the surface
Felt
no reports yet
Nearest
Mason County, 26 km W
Nearest mapped fault
Tacoma fault, 7 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 2492 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Tacoma, 30 km away, the estimate is intensity II (weak). 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.

Earthquakes near other towns within 30 km: Home, Key Center, Allyn, Longbranch, Rosedale, Belfair.

How big was it?

This earthquake released about 47 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 320,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 230,000× the energy of this one
  3. Around the size people start to feel M 3.0 20× the energy of this one
  4. This earthquake M 2.1 about 47 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 870 times the energy of this one.

Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.8 The 2001 Nisqually, Washington Earthquake · 20 km SSE of this epicentre
  2. 6.7 4 km WNW of Roy, Washington · 38 km SSE of this epicentre
  3. 6.7 1 km ENE of Dash Point, Washington · 32 km E of this epicentre
  4. 6.1 Puget Sound region, Washington · 12 km NNE of this epicentre
  5. 5.8 Puget Sound area, Washington · 6 km SW 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 47.3087, -122.8392. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mason County, WA 26 km (16 mi) W earthquakes near Mason County
Kitsap County, WA 39 km (25 mi) NNE earthquakes near Kitsap County
Thurston County, WA 41 km (26 mi) S earthquakes near Thurston County
Pierce County, WA 59 km (37 mi) ESE earthquakes near Pierce County
Jefferson County, WA 76 km (47 mi) NW earthquakes near Jefferson County
Grays Harbor County, WA 78 km (48 mi) WSW earthquakes near Grays Harbor County

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

Aftershocks so far

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

  1. 1.6 10 km SW of Brinnon, Washington
  2. 2.0 0 km N of Enetai, Washington
  3. 1.8 1 km SW of Enetai, Washington
  4. 1.6 2 km S of Bainbridge Island, Washington
  5. 2.4 0 km SE of Enetai, Washington
  6. 1.7 1 km S of Southworth, Washington
  7. 1.6 3 km N of Silverdale, Washington
  8. 1.6 4 km W of Seabeck, Washington
  9. 1.7 3 km ENE of Enetai, Washington
  10. 1.5 2 km NNW of Manchester, Washington
  11. 2.2 1 km E of Enetai, Washington
  12. 1.9 0 km N of Vaughn, Washington
  13. 1.5 5 km W of Gorst, Washington
  14. 2.4 0 km NE of Enetai, Washington
  15. 2.0 2 km NE of Enetai, 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.