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 1:30 pm PST (21:30 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 7 km (4 mi) northeast of Lower Lake, CA, at 5:55 pm PST on 21 January 2021 (01:55 UTC), less than 1 km deep. 1 person has reported feeling it to USGS.
USGS: 7km NE of Lower Lake, CA
57 km (36 mi) NNE of Santa Rosa, CA · 130 km (81 mi) N of San Francisco, CA
- When
- 5:55 pm PST on 21 January 2021 ()
- Where
- 7 km (4 mi) northeast of Lower Lake, CA · earthquakes near Lower Lake
- Magnitude
- M 1.7 (md)
- Depth
- -0.2 km below the surface
- Felt
- 1 report · strongest reported intensity II
- Nearest
- Lake County, 25 km NW
- Nearest mapped fault
- Hunting Creek-Berryessa fault system, 5 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 2117 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 12 km (7 mi) from the epicentre. In Lower Lake, 7 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: Clearlake 7 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 9.6 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 99× the energy of this one
- This earthquake M 1.7 about 9.6 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 130,000 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 38.9480, -122.5483. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Lake County, CA | 25 km (15 mi) | NW | earthquakes near Lake County |
| Colusa County, CA | 37 km (23 mi) | NE | earthquakes near Colusa County |
| Napa County, CA | 53 km (33 mi) | SSE | earthquakes near Napa County |
| Sonoma County, CA | 57 km (36 mi) | SW | earthquakes near Sonoma County |
| Yolo County, CA | 63 km (39 mi) | ESE | earthquakes near Yolo County |
| Sutter County, CA | 74 km (46 mi) | E | earthquakes near Sutter County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
56 earthquakes have been recorded within 50 km since this one.
- 2.4 2km NE of The Geysers, CA
- 1.7 12km W of Lakeport, CA
- 1.9 5km WNW of The Geysers, CA
- 1.6 3km SE of The Geysers, CA
- 1.6 7km WNW of The Geysers, CA
- 1.9 0km NW of The Geysers, CA
- 1.7 0km N of The Geysers, CA
- 1.7 2km W of Anderson Springs, CA
- 1.8 4km SE of The Geysers, CA
- 2.0 8km W of Cobb, CA
- 1.8 2km W of Anderson Springs, CA
- 1.9 2km NNE of The Geysers, CA
- 2.0 7km NW of The Geysers, CA
- 1.6 8km NE of Windsor, CA
- 2.0 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.