explosion · reviewed by a seismologist
M 1.7ml
Earthquake near Portland, OR
No earthquake was likely felt in Portland in the 24 hours to 5:06 am PST (13:06 UTC). The last one was M 4.4, 110 km (68 mi) S, at 5:52 am PDT on 7 October 2022, estimated intensity II (weak) in town; 6,105 felt reports to USGS. Every earthquake near Portland
No: USGS classifies this as a explosion, not an earthquake. A magnitude 1.7 explosion was recorded 42 km (26 mi) north-northeast of Portland, OR, at 3:54 pm PDT on 21 August 2023 (22:54 UTC), less than 1 km deep.
USGS: Washington-Oregon border region
40 km (25 mi) NNE of Portland, OR · 28 km (18 mi) NNE of Vancouver, WA
- When
- 3:54 pm PDT on 21 August 2023 ()
- Where
- 42 km (26 mi) north-northeast of Portland, OR · earthquakes near Portland
- Magnitude
- M 1.7 (ml)
- Depth
- -0.7 km below the surface
- Felt
- no reports yet
- Nearest
- Clark County, 11 km SSW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1179 days ago
Earthquake alerts for Portland, OR
Get a notification in this browser when USGS records an earthquake near Portland, OR. 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 Portland, 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: Yacolt, Amboy, Venersborg, Lewisville, Battle Ground, Hockinson.
USGS catalogues this as explosion, not an earthquake.
How big was it?
This earthquake released about 10 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 1,500,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
- Around the size people start to feel M 3.0 95× the energy of this one
- This earthquake M 1.7 about 10 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.
Where
Epicentre 45.8580, -122.4132. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Clark County, WA | 11 km (7 mi) | SSW | earthquakes near Clark County |
| Multnomah County, OR | 35 km (21 mi) | S | earthquakes near Multnomah County |
| Skamania County, WA | 40 km (25 mi) | ENE | earthquakes near Skamania County |
| Cowlitz County, WA | 43 km (27 mi) | NNW | earthquakes near Cowlitz County |
| Columbia County, OR | 53 km (33 mi) | W | earthquakes near Columbia County |
| Washington County, OR | 63 km (39 mi) | WSW | earthquakes near Washington County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
55 earthquakes have been recorded within 50 km since this one.
- 1.6 3 km NNE of Washougal, Washington
- 1.6 5 km ENE of Prescott, Oregon
- 1.5 14 km NE of Amboy, Washington
- 2.2 0 km SE of Barberton, Washington
- 1.5 24 km N of Amboy, Washington
- 1.5 37 km NNE of Amboy, Washington
- 2.0 30 km N of Amboy, Washington
- 1.6 1 km WSW of Kalama, Washington
- 1.7 24 km N of Amboy, Washington
- 2.1 24 km N of Amboy, Washington
- 1.7 4 km NNE of Kalama, Washington
- 1.8 5 km WNW of Deer Island, Oregon
- 2.3 19 km E of Kelso, Washington
- 2.0 19 km E of Kelso, Washington
- 1.5 9 km ENE of Kalama, 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.