Earthquake · reviewed by a seismologist
M 1.7md
Earthquake near Lower Lake, CA
No earthquake was likely felt in Lower Lake in the 24 hours to 11:45 pm PST (07:45 UTC). The last one was M 2.6, 19 km (12 mi) SW, at 4:44 pm PST on 8 November 2026, estimated intensity II (weak) in town. Every earthquake near Lower Lake
This page: a magnitude 1.7 earthquake was recorded 8 km (5 mi) east-northeast of Lower Lake, CA, at 6:21 am PST on 23 February 2020 (14:21 UTC), 9.3 km deep.
USGS: 8km ENE of Lower Lake, CA
56 km (35 mi) NNE of Santa Rosa, CA · 128 km (79 mi) N of San Francisco, CA
- When
- 6:21 am PST on 23 February 2020 ()
- Where
- 8 km (5 mi) east-northeast of Lower Lake, CA · earthquakes near Lower Lake
- Magnitude
- M 1.7 (md)
- Depth
- 9.3 km below the surface
- Felt
- no reports yet
- Nearest
- Lake County, 28 km NW
- Nearest mapped fault
- Hunting Creek-Berryessa 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 2452 days ago
Earthquake alerts for Lower Lake, CA
Get a notification in this browser when USGS records an earthquake near Lower 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 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 7 km (4 mi) from the epicentre. In Lower Lake, 8 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: Clearlake, Hidden Valley Lake, Clearlake Oaks, Clear Lake Riviera, Middletown, Cobb.
How big was it?
This earthquake released about 9.3 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,600,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
- Around the size people start to feel M 3.0 100× the energy of this one
- This earthquake M 1.7 about 9.3 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 5.0 on 2016-12-14 — about 110,000 times the energy of this one.
Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.
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 38.9272, -122.5155. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Lake County, CA | 28 km (18 mi) | NW | earthquakes near Lake County |
| Colusa County, CA | 37 km (23 mi) | NE | earthquakes near Colusa County |
| Napa County, CA | 50 km (31 mi) | SSE | earthquakes near Napa County |
| Sonoma County, CA | 57 km (36 mi) | SW | earthquakes near Sonoma County |
| Yolo County, CA | 60 km (37 mi) | ESE | earthquakes near Yolo County |
| Sutter County, CA | 71 km (44 mi) | E | earthquakes near Sutter 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.
- 1.8 8km NW of The Geysers, CA
- 1.5 7km NW of The Geysers, CA
- 1.5 8km NW of The Geysers, CA
- 1.7 7km NW of The Geysers, CA
- 1.5 1km NNW of The Geysers, CA
- 2.9 7km WNW of The Geysers, CA
- 1.9 3km NNE of The Geysers, CA
- 2.0 2km NW of The Geysers, CA
- 1.7 1km NW of The Geysers, CA
- 1.7 3km SW of Anderson Springs, CA
- 1.5 7km NW of The Geysers, CA
- 1.9 3km SSW of Anderson Springs, CA
- 1.6 6km NW of The Geysers, CA
- 1.9 10km SSW of Kelseyville, CA
- 1.5 7km NW of The Geysers, 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.