Earthquake · reviewed by a seismologist
M 1.5md
Earthquake near Upper Lake, CA
No earthquake was likely felt in Upper Lake in the 24 hours to 10:16 pm PST (06:16 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 1.5 earthquake was recorded 4 km (3 mi) north of Upper Lake, CA, at 10:13 am PDT on 16 April 2018 (17:13 UTC), 9.7 km deep.
USGS: 4km N of Upper Lake, CA
- When
- 10:13 am PDT on 16 April 2018 ()
- Where
- 4 km (3 mi) north of Upper Lake, CA · earthquakes near Upper Lake
- Magnitude
- M 1.5 (md)
- Depth
- 9.7 km below the surface
- Felt
- no reports yet
- Nearest
- Lake County, 18 km SE
- Nearest mapped fault
- Bartlett Springs fault system, 10 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 3127 days ago
Earthquake alerts for Upper Lake, CA
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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 3 km (2 mi) from the epicentre. In Upper Lake, 4 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.
Earthquakes near other towns within 30 km: Nice, North Lakeport, Lakeport, Talmage, Soda Bay, Kelseyville.
How big was it?
This earthquake released about 5.4 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 2,800,000× the energy of this one
- Magna, Utah 2020 M 5.7 2,000,000× 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 5.4 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 240,000 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 · 18 km WSW 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 39.2025, -122.9143. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Lake County, CA | 18 km (11 mi) | SE | earthquakes near Lake County |
| Mendocino County, CA | 52 km (32 mi) | WNW | earthquakes near Mendocino County |
| Colusa County, CA | 58 km (36 mi) | E | earthquakes near Colusa County |
| Glenn County, CA | 63 km (39 mi) | NE | earthquakes near Glenn County |
| Sonoma County, CA | 75 km (47 mi) | S | earthquakes near Sonoma County |
| Napa County, CA | 93 km (58 mi) | SSE | earthquakes near Napa County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
60 earthquakes have been recorded within 50 km since this one.
- 1.6 3km W of Cobb, CA
- 1.7 8km SE of Lake Pillsbury, CA
- 1.7 6km WNW of The Geysers, CA
- 1.8 6km WNW of Cobb, CA
- 1.5 6km NW of The Geysers, CA
- 2.6 6km WNW of Cobb, CA
- 1.8 11km NNE of Redwood Valley, CA
- 2.8 7km WNW of The Geysers, CA
- 1.5 5km NNW of The Geysers, CA
- 2.1 6km W of Cobb, CA
- 3.0 19km NE of Upper Lake, CA
- 1.7 6km NW of The Geysers, CA
- 1.8 7km WNW of The Geysers, CA
- 1.6 7km NW of The Geysers, CA
- 1.9 3km WNW of Lower Lake, 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.