explosion · reviewed by a seismologist
M 1.7ml
Earthquake near Sweet Home, OR
No earthquake was likely felt in Sweet Home in the 24 hours to 10:11 am PST (18:11 UTC). The last one was M 2.0, 4 km (3 mi) N, at 4:16 pm PDT on 2 September 2025, estimated intensity II (weak) in town. Every earthquake near Sweet Home
No: USGS classifies this as a explosion, not an earthquake. A magnitude 1.7 explosion was recorded 29 km (18 mi) southeast of Sweet Home, OR, at 10:56 am PDT on 4 August 2023 (17:56 UTC), less than 1 km deep.
USGS: 16 km SSE of Cascadia, Oregon
49 km (30 mi) ENE of Springfield, OR · 144 km (89 mi) S of Portland, OR
- When
- 10:56 am PDT on 4 August 2023 ()
- Where
- 29 km (18 mi) southeast of Sweet Home, OR · earthquakes near Sweet Home
- Magnitude
- M 1.7 (ml)
- Depth
- -0.9 km below the surface
- Felt
- no reports yet
- Nearest
- Linn County, 28 km NNW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1197 days ago
Earthquake alerts for Sweet Home, OR
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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 13 km (8 mi) from the epicentre. In Sweet Home, 29 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.
USGS catalogues this as explosion, not an earthquake.
How big was it?
This earthquake released about 12 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.
- Mineral, Virginia 2011 M 5.8 1,200,000× the energy of this one
- Magna, Utah 2020 M 5.7 870,000× the energy of this one
- Around the size people start to feel M 3.0 78× the energy of this one
- This earthquake M 1.7 about 12 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 4.4 on 2022-10-07 — about 9,400 times the energy of this one.
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 44.2510, -122.4368. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Linn County, OR | 28 km (17 mi) | NNW | earthquakes near Linn County |
| Lane County, OR | 51 km (32 mi) | SW | earthquakes near Lane County |
| Marion County, OR | 73 km (45 mi) | N | earthquakes near Marion County |
| Benton County, OR | 83 km (52 mi) | WNW | earthquakes near Benton County |
| Clackamas County, OR | 103 km (64 mi) | N | earthquakes near Clackamas County |
| Deschutes County, OR | 104 km (64 mi) | ESE | earthquakes near Deschutes County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
28 earthquakes have been recorded within 50 km since this one.
- 1.5 13 km S of Crawfordsville, Oregon
- 0.4 24 km ENE of Unity, Oregon
- 1.8 5 km NW of Lacomb, Oregon
- 1.6 5 km NW of Lacomb, Oregon
- 1.7 14 km NE of Springfield, Oregon
- 2.0 6 km W of Lacomb, Oregon
- 1.6 9 km SSE of Crawfordsville, Oregon
- 1.5 4 km SSE of Cascadia, Oregon
- 1.5 1 km NNE of Cascadia, Oregon
- 2.0 4 km N of Sweet Home, Oregon
- 1.8 5 km N of Waterloo, Oregon
- 1.5 3 km S of Brownsville, Oregon
- 1.6 22 km N of Unity, Oregon
- 1.9 5 km ENE of Lebanon, Oregon
- 2.2 3 km NNW of Sweet Home, Oregon
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.