QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9ml

Earthquake near Tacoma, WA

No earthquake was likely felt in Tacoma in the 24 hours to 4:02 pm PST (00:02 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 1.9 earthquake was recorded 7 km (4 mi) north-northeast of Tacoma, WA, at 3:47 am PDT on 8 October 2018 (10:47 UTC), 18 km deep. 1 person has reported feeling it to USGS.

USGS: 1 km SE of Dash Point, Washington

7 km (5 mi) NNE of Tacoma, WA · 6 km (3 mi) W of Federal Way, WA

3:47 am PDT, Oct 8, 2018 · · 18 km deep · released about 19 lb of TNT

10 km30 km60 km120 km N Pierce County 35 kmKitsap County 41 kmKing County 48 kmThurston County 52 kmMason County 58 kmLewis County 81 kmSnohomish County 96 kmIsland County 96 kmJefferson County 100 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
3:47 am PDT on 8 October 2018 ()
Where
7 km (4 mi) north-northeast of Tacoma, WA · earthquakes near Tacoma
Magnitude
M 1.9 (ml)
Depth
18 km below the surface
Felt
1 report · strongest reported intensity I
Nearest
Pierce County, 35 km SE
Nearest mapped fault
Tacoma fault, 1 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 1559 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, 7 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: Browns Point, Fife Heights, Federal Way, Fife, Milton, Lakeland South.

How big was it?

This earthquake released about 19 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 810,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 580,000× the energy of this one
  3. Around the size people start to feel M 3.0 51× the energy of this one
  4. This earthquake M 1.9 about 19 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 lists 6 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.8 The 2001 Nisqually, Washington Earthquake · 30 km SW of this epicentre
  2. 6.7 4 km WNW of Roy, Washington · 36 km SSW of this epicentre
  3. 6.7 1 km ENE of Dash Point, Washington · 2 km N of this epicentre
  4. 6.1 Puget Sound region, Washington · 28 km WNW of this epicentre
  5. 5.8 Puget Sound area, Washington · 37 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 47.3095, -122.4110. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Pierce County, WA 35 km (22 mi) SE earthquakes near Pierce County
Kitsap County, WA 41 km (25 mi) NNW earthquakes near Kitsap County
King County, WA 48 km (30 mi) ENE earthquakes near King County
Thurston County, WA 52 km (32 mi) SW earthquakes near Thurston County
Mason County, WA 58 km (36 mi) W earthquakes near Mason County
Lewis County, WA 81 km (50 mi) S earthquakes near Lewis 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. 1.7 3 km ENE of Enetai, Washington
  2. 1.7 1 km SSE of Kapowsin, Washington
  3. 2.1 Puget Sound region, Washington
  4. 1.5 3 km ENE of Enetai, Washington
  5. 1.6 1 km SW of Keyport, Washington
  6. 1.5 2 km N of Boulevard Park, Washington
  7. 1.5 3 km SW of Kapowsin, Washington
  8. 1.8 1 km N of Fairwood, Washington
  9. 2.0 1 km ENE of Enetai, Washington
  10. 1.7 1 km SE of Kapowsin, Washington
  11. 1.6 4 km SE of Ames Lake, Washington
  12. 2.0 4 km WNW of Gorst, Washington
  13. 1.7 5 km N of Belfair, Washington
  14. 1.6 6 km WNW of DuPont, Washington
  15. 2.1 6 km NNE of Olympia, 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.