Earthquake · reviewed by a seismologist
M 3.0ml
Earthquake near Upper Lake, CA
No earthquake was likely felt in Upper Lake in the 24 hours to 9:12 pm PST (05:12 UTC). The last one was M 1.6, 8 km (5 mi) W, at 4:31 am PST on 10 November 2026, estimated intensity II (weak) in town. Every earthquake near Upper Lake
This page: a magnitude 3.0 earthquake was recorded 19 km (12 mi) northeast of Upper Lake, CA, at 1:26 pm PDT on 4 May 2018 (20:26 UTC), 12 km deep. 18 people have reported feeling it to USGS.
USGS: 19km NE of Upper Lake, CA
- When
- 1:26 pm PDT on 4 May 2018 ()
- Where
- 19 km (12 mi) northeast of Upper Lake, CA · earthquakes near Upper Lake
- Magnitude
- M 3.0 (ml)
- Depth
- 12 km below the surface
- Felt
- 18 reports · strongest reported intensity III
- Nearest
- Lake County, 22 km S
- Nearest mapped fault
- Bartlett Springs fault system, 4 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 3029 days ago
Earthquake alerts for Upper Lake, CA
Get a notification in this browser when USGS records an earthquake near Upper Lake, 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 37 km (23 mi) from the epicentre. In Upper Lake, 19 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: Upper Lake 19 km, intensity II · Lakeport 31 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 1,100 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 310,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 14,000× the energy of this one
- Magna, Utah 2020 M 5.7 9,800× the energy of this one
- This earthquake M 3.0 about 1,100 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 1,200 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 · 35 km SW 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 39.3032, -122.7735. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Lake County, CA | 22 km (14 mi) | S | earthquakes near Lake County |
| Glenn County, CA | 46 km (29 mi) | NE | earthquakes near Glenn County |
| Colusa County, CA | 48 km (30 mi) | ESE | earthquakes near Colusa County |
| Mendocino County, CA | 59 km (37 mi) | WNW | earthquakes near Mendocino County |
| Sonoma County, CA | 88 km (54 mi) | S | earthquakes near Sonoma County |
| Napa County, CA | 97 km (60 mi) | SSE | earthquakes near Napa County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
52 earthquakes have been recorded within 50 km since this one.
- 1.7 6km SE of Lake Pillsbury, CA
- 1.5 2km WNW of Kelseyville, CA
- 1.6 10km N of Lake Pillsbury, CA
- 2.5 5km NE of Willits, CA
- 1.8 7km SE of Willits, CA
- 2.0 7km SE of Willits, CA
- 1.8 7km W of Redwood Valley, CA
- 1.8 9km SE of Lake Pillsbury, CA
- 1.8 3km NW of Redwood Valley, CA
- 1.6 9km SSE of Lake Pillsbury, CA
- 1.8 17km SE of Lake Pillsbury, CA
- 2.2 18km NE of Upper Lake, CA
- 1.5 15km NE of Upper Lake, CA
- 1.6 10km N of Lake Pillsbury, CA
- 1.9 10km N of Lake Pillsbury, 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.