Earthquake · reviewed by a seismologist
M 2.8md
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 2.8 earthquake was recorded 38 km (24 mi) north-northeast of Ukiah, CA, at 9:48 am PDT on 8 April 2018 (16:48 UTC), 3.7 km deep. 1 person has reported feeling it to USGS.
USGS: 16km WNW of Lake Pillsbury, CA
- When
- 9:48 am PDT on 8 April 2018 ()
- Where
- 38 km (24 mi) north-northeast of Ukiah, CA · earthquakes near Ukiah
- Magnitude
- M 2.8 (md)
- Depth
- 3.7 km below the surface
- Felt
- 1 report · strongest reported intensity II
- Nearest
- Mendocino County, 29 km WSW
- Nearest mapped fault
- Bartlett Springs fault system, 9 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 3135 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 small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.
At this magnitude and depth, people at rest would likely notice it out to about 29 km (18 mi) from the epicentre. In Ukiah, 38 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.
Likely felt in: Willits 22 km, intensity II · Brooktrails 24 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 550 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 28,000× the energy of this one
- Magna, Utah 2020 M 5.7 19,000× the energy of this one
- Around the size people start to feel M 3.0 1.7× the energy of this one
- This earthquake M 2.8 about 550 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 2,400 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 · 41 km S 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 39.4848, -123.1155. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Mendocino County, CA | 29 km (18 mi) | WSW | earthquakes near Mendocino County |
| Lake County, CA | 53 km (33 mi) | SE | earthquakes near Lake County |
| Glenn County, CA | 63 km (39 mi) | ENE | earthquakes near Glenn County |
| Colusa County, CA | 83 km (51 mi) | ESE | earthquakes near Colusa County |
| Tehama County, CA | 104 km (65 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
55 earthquakes have been recorded within 50 km since this one.
- 1.7 3km WNW of Redwood Valley, CA
- 1.6 5km NW of Laytonville, CA
- 2.5 10km N of Lake Pillsbury, CA
- 1.7 18km SE of Lake Pillsbury, CA
- 1.9 13km N of Brooktrails, CA
- 1.8 7km ENE of Covelo, CA
- 1.8 4km NNW of Redwood Valley, CA
- 1.6 7km E of Lake Pillsbury, CA
- 1.6 9km NNW of Redwood Valley, CA
- 1.8 28km NNW of Alder Springs, CA
- 1.8 6km SE of Lake Pillsbury, CA
- 1.9 18km NE of Upper Lake, CA
- 1.9 17km NE of Upper Lake, CA
- 2.4 4km NNW of Laytonville, CA
- 1.6 7km SW of Laytonville, 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.