explosion · reviewed by a seismologist
M 1.6ml
Earthquake near Chewelah, WA
USGS: 5 km WSW of Addy, Washington
82 km (51 mi) NNW of Spokane, WA
- When
- 11:11 am PDT on 25 September 2020 ()
- Where
- 15 km (9 mi) WNW of Chewelah, WA · earthquakes near Chewelah
- Magnitude
- M 1.6 (ml)
- Depth
- -0.6 km below the surface
- Felt
- no reports yet
- Nearest
- Stevens County, 7 km NNE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2198 days ago
A magnitude 1.6 earthquake was recorded 15 km (9 mi) WNW of Chewelah, WA, at 11:11 am PDT on 25 September 2020 (18:11 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
Earthquakes near other towns within 30 km: Colville.
USGS catalogues this as explosion, not an earthquake.
How big was it?
This earthquake released about 9 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 1,700,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,200,000× 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 9 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 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 48.3357, -117.8993. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Stevens County, WA | 7 km (4 mi) | NNE | earthquakes near Stevens County |
| Ferry County, WA | 49 km (31 mi) | WNW | earthquakes near Ferry County |
| Pend Oreille County, WA | 54 km (34 mi) | ENE | earthquakes near Pend Oreille County |
| Spokane County, WA | 88 km (54 mi) | SSE | earthquakes near Spokane County |
| Lincoln County, WA | 92 km (57 mi) | SSW | earthquakes near Lincoln County |
| Bonner County, ID | 94 km (58 mi) | E | earthquakes near Bonner County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
15 earthquakes have been recorded within 50 km since this one.
- 1.1 12 km WNW of Springdale, Washington
- 1.5 13 km W of Valley, Washington
- 1.6 14 km WNW of Valley, Washington
- 1.6 17 km SE of Inchelium, Washington
- 1.7 5 km NW of Colville, Washington
- 1.8 6 km S of Valley, Washington
- 1.7 23 km NW of Inchelium, Washington
- 1.8 10 km WNW of Valley, Washington
- 1.5 6 km ESE of Kettle Falls, Washington
- 1.9 6 km ESE of Kettle Falls, Washington
- 1.5 11 km WSW of Valley, Washington
- 1.8 12 km WNW of Valley, Washington
- 1.6 8 km W of Valley, Washington
- 1.9 6 km NW of Colville, Washington
- 1.8 8 km NW of Springdale, 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.