Light mag. 3.2 earthquake - Sonoma County, 4.8 mi west of Cobb, California, USA, on Friday, 4 Dec 2020 2:48 am (GMT -8) -
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Light magnitude 3.2 earthquake at 4 km depth
4 Dec 10:51 UTC: First to report: USGS after 2 minutes.
Update Fri, 4 Dec 2020, 10:54
Small magnitude 3.2 earthquake 5 miles west of Cobb, California, United States3.2 quake 4.8 mi west of Cobb, California, USA, 4 Dec 2.48 am (GMT -8)
A very shallow magnitude 3.2 earthquake was reported early morning near Cobb, Lake County, California, USA.
According to the United States Geological Survey (USGS), the quake hit on Friday 4 December 2020 at 2.48 am local time at a very shallow depth of 2.2 miles. Shallow earthquakes are felt more strongly than deeper ones as they are closer to the surface. The exact magnitude, epicenter, and depth of the quake might be revised within the next few hours or minutes as seismologists review data and refine their calculations, or as other agencies issue their report.
Based on the preliminary seismic data, the quake should not have caused any significant damage, but was probably felt by many people as light vibration in the area of the epicenter.
Weak shaking might have been felt in Cobb (pop. 1,800) located 5 miles from the epicenter.
Other towns or cities near the epicenter where the quake might have been felt as very weak shaking include Cloverdale (pop. 8,800) located 11 miles from the epicenter, Middletown (pop. 1,300) 11 miles away, Kelseyville (pop. 3,400) 11 miles away, Hidden Valley Lake (pop. 5,600) 14 miles away, Clearlake (pop. 15,200) 14 miles away, Healdsburg (pop. 11,700) 14 miles away, and Windsor (pop. 27,500) 18 miles away.
According to the United States Geological Survey (USGS), the quake hit on Friday 4 December 2020 at 2.48 am local time at a very shallow depth of 2.2 miles. Shallow earthquakes are felt more strongly than deeper ones as they are closer to the surface. The exact magnitude, epicenter, and depth of the quake might be revised within the next few hours or minutes as seismologists review data and refine their calculations, or as other agencies issue their report.
Based on the preliminary seismic data, the quake should not have caused any significant damage, but was probably felt by many people as light vibration in the area of the epicenter.
Weak shaking might have been felt in Cobb (pop. 1,800) located 5 miles from the epicenter.
Other towns or cities near the epicenter where the quake might have been felt as very weak shaking include Cloverdale (pop. 8,800) located 11 miles from the epicenter, Middletown (pop. 1,300) 11 miles away, Kelseyville (pop. 3,400) 11 miles away, Hidden Valley Lake (pop. 5,600) 14 miles away, Clearlake (pop. 15,200) 14 miles away, Healdsburg (pop. 11,700) 14 miles away, and Windsor (pop. 27,500) 18 miles away.
Earthquake data:
Date & time: 4 Dec 2020 10:48:50 UTC -
Local time at epicenter: Friday, 4 Dec 2020 2:48 am (GMT -8)
Magnitude: 3.2
Depth: 3.6 km
Epicenter latitude / longitude: 38.81333°N / 122.8115°W

Nearest volcano: Clear Lake (18 km / 11 mi)
Nearby towns and cities:
8 km (5 mi) W of Cobb (pop: 1,780) --> See nearby quakes!
18 km (11 mi) E of Cloverdale (Sonoma County) (pop: 8,810) --> See nearby quakes!
23 km (14 mi) SW of Clearlake (Lake County) (pop: 15,200) --> See nearby quakes!
23 km (14 mi) NNE of Healdsburg (Sonoma County) (pop: 11,700) --> See nearby quakes!
23 km (14 mi) NNE of Russian River (pop: 11,700) --> See nearby quakes!
30 km (18 mi) N of Windsor (Sonoma County) (pop: 27,500) --> See nearby quakes!
42 km (26 mi) NNW of Santa Rosa (pop: 175,000) --> See nearby quakes!
54 km (33 mi) N of Rohnert Park (pop: 42,400) --> See nearby quakes!
117 km (73 mi) WNW of Sacramento (pop: 490,700) --> See nearby quakes!
120 km (75 mi) NNW of San Francisco (pop: 864,800) --> See nearby quakes!
Weather at epicenter at time of quake:
Clear Sky
4.8°C (41 F), humidity: 93%, wind: 1 m/s (3 kts) from NE
Primary data source: USGS (United States Geological Survey)Clear Sky

Estimated released energy: 4 x 109 joules (1.11 megawatt hours, equivalent to 0.951 tons of TNT) More info
Data for the same earthquake reported by different agencies
Info: The more agencies report about the same quake and post similar data, the more confidence you can have in the data. It takes normally up to a few hours until earthquake parameters are calculated with near-optimum precision.
Magnitude | Depth | Location | Source |
3.2 | 3.6 km | 6km NW of The Geysers, CA, USA | USGS |
User reports for this quake (3)
User reports estimate the perceived ground shaking intensity according to the MMI (Modified Mercalli Intensity) scale.