Earthquake · reviewed by a seismologist
M 1.6md
Earthquake near Ukiah, CA
Yes: an earthquake was likely felt in Ukiah in the last 24 hours. M 1.5, 10 km (6 mi) NE of Ukiah, at 12:31 pm PST on 11 November 2026 (20:31 UTC); the estimated shaking in Ukiah was intensity II (weak). Every earthquake near Ukiah
This page: a magnitude 1.6 earthquake was recorded 45 km (28 mi) north-northeast of Ukiah, CA, at 10:44 pm PDT on 15 August 2021 (05:44 UTC), 7.2 km deep. 1 person has reported feeling it to USGS.
USGS: 10km N of Lake Pillsbury, CA
- When
- 10:44 pm PDT on 15 August 2021 ()
- Where
- 45 km (28 mi) north-northeast of Ukiah, CA · earthquakes near Ukiah
- Magnitude
- M 1.6 (md)
- Depth
- 7.2 km below the surface
- Felt
- 1 report
- Nearest
- Mendocino County, 44 km W
- Nearest mapped fault
- Bartlett Springs fault system, 3 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 1912 days ago
Earthquake alerts for Ukiah, CA
Get a notification in this browser when USGS records an earthquake near Ukiah, CA. 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 9 km (6 mi) from the epicentre. In Ukiah, 45 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.
How big was it?
This earthquake released about 8.7 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 8.7 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 5.1 on 2016-08-10 — about 150,000 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 · 44 km SSW 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 39.4960, -122.9412. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Mendocino County, CA | 44 km (27 mi) | W | earthquakes near Mendocino County |
| Lake County, CA | 46 km (29 mi) | SSE | earthquakes near Lake County |
| Glenn County, CA | 48 km (30 mi) | ENE | earthquakes near Glenn County |
| Colusa County, CA | 70 km (44 mi) | ESE | earthquakes near Colusa County |
| Tehama County, CA | 93 km (58 mi) | NE | earthquakes near Tehama County |
| Sonoma County, CA | 108 km (67 mi) | S | earthquakes near Sonoma County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
54 earthquakes have been recorded within 50 km since this one.
- 1.6 7km NE of Brooktrails, CA
- 1.7 18km ENE of Nice, CA
- 2.8 6km E of Willits, CA
- 1.7 7km E of Willits, CA
- 2.1 9km SE of Willits, CA
- 1.7 8km E of Willits, CA
- 2.4 8km E of Willits, CA
- 1.5 6km E of Willits, CA
- 1.6 17km NW of Lake Pillsbury, CA
- 1.8 13km SE of Laytonville, CA
- 1.8 13km SE of Laytonville, CA
- 1.8 17km NW of Lake Pillsbury, CA
- 1.6 12km WNW of Redwood Valley, CA
- 1.7 18km SE of Lake Pillsbury, CA
- 1.8 8km 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.