explosion · reviewed by a seismologist
M 1.6ml
Earthquake near Lacey, WA
No earthquake was likely felt in Lacey in the 24 hours to 2:17 pm PST (22:17 UTC). The last one was M 4.2, 41 km (26 mi) N, at 2:05 pm PDT on 29 September 2026, estimated intensity III (weak) in town; 9,329 felt reports to USGS. Every earthquake near Lacey
No: USGS classifies this as a explosion, not an earthquake. A magnitude 1.6 explosion was recorded 42 km (26 mi) south-southeast of Lacey, WA, at 11:35 am PDT on 22 October 2024 (18:35 UTC), less than 1 km deep.
USGS: 20 km NE of Onalaska, Washington
41 km (26 mi) SSE of Lacey, WA · 101 km (63 mi) S of Seattle, WA
- When
- 11:35 am PDT on 22 October 2024 ()
- Where
- 42 km (26 mi) south-southeast of Lacey, WA · earthquakes near Lacey
- Magnitude
- M 1.6 (ml)
- Depth
- -0.2 km below the surface
- Felt
- no reports yet
- Nearest
- Lewis County, 19 km SE
- Nearest mapped fault
- Olympia structure, 13 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 751 days ago
Earthquake alerts for Lacey, WA
Get a notification in this browser when USGS records an earthquake near Lacey, WA. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth, people at rest would likely notice it out to about 12 km (7 mi) from the epicentre. In Lacey, 42 km away, the estimate is intensity I (not felt). 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: Rainier, Yelm, Eatonville, Morton, North Yelm, Tenino.
USGS catalogues this as explosion, not an earthquake.
How big was it?
This earthquake released about 8.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,800,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,300,000× the energy of this one
- Around the size people start to feel M 3.0 110× the energy of this one
- This earthquake M 1.6 about 8.4 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 2 earthquakes of M5 or more within 50 km:
- 6.7 4 km WNW of Roy, Washington · 33 km N of this epicentre
- 5.2 23 km S of Morton, Washington · 47 km SSE 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 46.7165, -122.5365. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Lewis County, WA | 19 km (12 mi) | SE | earthquakes near Lewis County |
| Thurston County, WA | 33 km (21 mi) | NW | earthquakes near Thurston County |
| Pierce County, WA | 47 km (29 mi) | NE | earthquakes near Pierce County |
| Cowlitz County, WA | 59 km (37 mi) | S | earthquakes near Cowlitz County |
| Wahkiakum County, WA | 83 km (51 mi) | SW | earthquakes near Wahkiakum County |
| Mason County, WA | 85 km (53 mi) | NW | earthquakes near Mason County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
48 earthquakes have been recorded within 50 km since this one.
- 1.6 6 km ESE of Mossyrock, Washington
- 1.7 13 km N of Onalaska, Washington
- 1.6 3 km W of Winlock, Washington
- 1.5 1 km WSW of Kapowsin, Washington
- 2.8 3 km NE of Mineral, Washington
- 1.9 6 km NE of Mossyrock, Washington
- 1.6 6 km ESE of Mossyrock, Washington
- 1.9 4 km WSW of Winlock, Washington
- 1.8 17 km WSW of Alder, Washington
- 1.6 1 km SSE of Kapowsin, Washington
- 1.7 8 km S of Mineral, Washington
- 1.8 1 km SE of Kapowsin, Washington
- 2.2 3 km NNE of Grand Mound, Washington
- 1.5 1 km SE of Kapowsin, Washington
- 1.8 9 km W of Napavine, 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.