Earthquake · automatic estimate, may change
M 1.5md
Earthquake near Redwood Valley, CA
USGS: 11 km N of Redwood Valley, CA
- When
- 7:38 pm PDT on 28 September 2026 ()
- Where
- 11 km (7 mi) N of Redwood Valley, CA · earthquakes near Redwood Valley
- Magnitude
- M 1.5 (md)
- Depth
- 8.2 km below the surface
- Felt
- no reports yet
- Nearest
- Mendocino County, 21 km WNW
- Nearest mapped fault
- Maacama fault, 9 km from its surface trace — near is not the same as on
- Status
- Automatic — a machine’s first estimate, which may change
USGS · last changed by USGS · we first saw it 4 days ago
A magnitude 1.5 earthquake was recorded 11 km (7 mi) N of Redwood Valley, CA, at 7:38 pm PDT on 28 September 2026 (02:38 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
Earthquakes near other towns within 30 km: Willits, Brooktrails, Ukiah, Talmage.
How big was it?
This earthquake released about 5.2 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 2,900,000× the energy of this one
- Magna, Utah 2020 M 5.7 2,100,000× the energy of this one
- Around the size people start to feel M 3.0 180× the energy of this one
- This earthquake M 1.5 about 5.2 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 5.6 on 2026-06-24 — about 1,400,000 times the energy of this one.
Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:
- 5.2 6 km ESE of Talmage, California · 29 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 39.3602, -123.2118. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Mendocino County, CA | 21 km (13 mi) | WNW | earthquakes near Mendocino County |
| Lake County, CA | 49 km (30 mi) | SE | earthquakes near Lake County |
| Glenn County, CA | 75 km (46 mi) | ENE | earthquakes near Glenn County |
| Colusa County, CA | 86 km (54 mi) | ESE | earthquakes near Colusa County |
| Sonoma County, CA | 96 km (60 mi) | SSE | earthquakes near Sonoma County |
| Tehama County, CA | 119 km (74 mi) | NE | earthquakes near Tehama County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
7 earthquakes have been recorded within 50 km since this one.
- 1.4 8 km SE of Willits, CA
- 2.1 17 km NE of Nice, CA
- 1.5 9 km NW of Redwood Valley, CA
- 2.2 10 km W of Boonville, CA
- 1.7 16 km NNE of Brooktrails, CA
- 2.2 6 km N of Redwood Valley, CA
- 1.0 1 km NNW of Redwood Valley, CA
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.