Light mag. 3.9 earthquake - 12 mi south of Fortuna, Humboldt County, California, USA, on Friday, 18 Dec 2020 8:13 am (GMT -8) -
Light magnitude 3.9 earthquake at 26 km depth
18 Dec 16:18 UTC: First to report: EMSC after 4 minutes.
18 Dec 16:18: Now using data updates from USGS
18 Dec 17:28: Magnitude recalculated from 3.8 to 3.9.
18 Dec 18:36: Hypocenter depth recalculated from 23.2 to 25.8 km (from 14.4 to 16 mi). Epicenter location corrected by 1.7 km (1.1 mi) towards WSW.
Update Fri, 18 Dec 2020, 16:24Magnitude 3.8 earthquake strikes near Fortuna, United States
3.8 quake 18 Dec 8:13 am (GMT -8)
The United States Geological Survey (USGS) reported a magnitude 3.8 quake in the United States near Fortuna, Humboldt County, California, only 10 minutes ago. The earthquake hit in the morning on Friday 18 December 2020 at 8:13 am local time at a shallow depth of 14 miles. 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.
A second report was later issued by the European-Mediterranean Seismological Centre (EMSC), which listed it as a magnitude 3.8 earthquake as well.
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 Scotia (pop. 850) located 7 miles from the epicenter.
Other towns or cities near the epicenter where the quake might have been felt as very weak shaking include Ferndale (pop. 1,400) located 10 miles from the epicenter, Fortuna (pop. 12,000) 12 miles away, Loleta (pop. 780) 14 miles away, Eureka (pop. 27,000) 26 miles away, Bayside (pop. 17,100) 29 miles away, Arcata (pop. 17,800) 31 miles away, and McKinleyville (pop. 15,200) 36 miles away.
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Date & time: 18 Dec 2020 16:13:42 UTC -
Local time at epicenter:
Friday, 18 Dec 2020 8:13 am (GMT -8)
Depth: 25.8 km
Epicenter latitude / longitude: 40.43117°N / 124.22917°W
, United States
Nearest volcano: Mount Shasta
(201 km / 125 mi)
Nearby towns and cities:12 km (8 mi) WSW of Scotia (Humboldt County)
(pop: 850) --> See nearby quakes!20 km (12 mi) SSW of Fortuna (Humboldt County)
(pop: 12,000) --> See nearby quakes!42 km (26 mi) S of Eureka (Humboldt County)
(pop: 27,000) --> See nearby quakes!48 km (30 mi) SSW of Bayside (Humboldt County)
(pop: 17,100) --> See nearby quakes!49 km (30 mi) NW of Redway
(pop: 1,230) --> See nearby quakes!50 km (31 mi) SSW of Arcata (Humboldt County)
(pop: 17,800) --> See nearby quakes!58 km (36 mi) S of McKinleyville (Humboldt County)
(pop: 15,200) --> See nearby quakes!76 km (47 mi) SW of Willow Creek
(pop: 1,710) --> See nearby quakes!156 km (97 mi) W of Redding
(pop: 91,600) --> See nearby quakes!312 km (194 mi) NW of Sacramento
(pop: 490,700) --> See nearby quakes!
Weather at epicenter at time of quake:
Broken Clouds 3°C
(37 F), humidity: 93%, wind: 5 m/s (10 kts) from ESE
Primary data source: USGS
(United States Geological Survey)
Estimated released energy: 4.5 x 1010
joules (12.4 megawatt hours, equivalent to 10.7 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.
|3.9||26 km||11km SW of Rio Dell, CA, USA||USGS|
|3.3||33 km||NORTHERN CALIFORNIA, USA||EMSC|
User reports for this quake (2)
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Sacramento, ca (2.5 km SE of epicenter) [Map] / Very weak shaking (MMI II) / rattling, vibrating / 10-15 s : Laying abed, 2nd floor of flexible, old wooden house, reading morning paper, companion asked do you feel that? That being a mattress vibration, and yes, we felt it, and then it again vibrated. Not strong or sharp as in years past when a quake rattled our hanging iron cookware. | 4 users found this interesting.
Sacramento / Very weak shaking (MMI II) / horizontal (sideways) swinging / 5-10 s
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