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Mag. 5.1 earthquake - North Pacific Ocean, 36 mi south of Eureka, Humboldt County, California, USA, on Saturday, Jul 17, 2021 11:46 pm (Los Angeles time)

Mag. 5.1 earthquake - North Pacific Ocean, 36 mi south of Eureka, Humboldt County, California, USA, on Saturday, Jul 17, 2021 11:46 pm (Los Angeles time) Mag. 5.1 earthquake - North Pacific Ocean, 36 mi south of Eureka, Humboldt County, California, USA, on Saturday, Jul 17, 2021 11:46 pm (Los Angeles time)

Moderate magnitude 5.1 earthquake at 31 km depth

18 Jul 06:51 UTC: First to report: USGS after 5 minutes.
18 Jul 09:20: Hypocenter depth recalculated from 27.0 to 30.9 km (from 16.8 to 19.2 mi). Epicenter location corrected by 7.4 km (4.6 mi) towards E.
Update Sun, 18 Jul 2021, 06:57

Magnitude 5.1 earthquake strikes near Eureka, Humboldt County, California, USA

5.1 quake 17 Jul 11:46 pm (GMT -7)
5.1 quake 17 Jul 11:46 pm (GMT -7)
An earthquake of magnitude 5.1 occurred only 11 minutes ago 38 miles southwest of Eureka, California, United States, the United States Geological Survey reported.
The quake hit at a shallow depth of 17 miles beneath the epicenter near Eureka, Humboldt County, California, USA, late at night on Saturday 17 July 2021 at 11:46 pm local time. 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 5.1 earthquake as well.
Based on the preliminary seismic data, the quake was probably felt by many people in the area of the epicenter. It should not have caused significant damage, other than objects falling from shelves, broken windows, etc.
In Ferndale (pop. 1,400) located 22 miles from the epicenter, the quake should have been felt as light shaking.
Weak shaking might have been felt in Rio Dell (pop. 3,400) located 25 miles from the epicenter, Fortuna (pop. 12,000) 27 miles away, Hydesville (pop. 1,200) 27 miles away, Eureka (pop. 27,000) 38 miles away, Bayside (pop. 17,100) 43 miles away, Arcata (pop. 17,800) 44 miles away, and McKinleyville (pop. 15,200) 49 miles away.
VolcanoDiscovery will automatically update magnitude and depth if these change and follow up if other significant news about the quake become available. If you're in the area, please send us your experience through our reporting mechanism, either online or via our mobile app. This will help us provide more first-hand updates to anyone around the globe who wants to know more about this quake.
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Earthquake details

Date & timeJul 18, 2021 06:46:12 UTC
Local time at epicenterSaturday, Jul 17, 2021 11:46 pm (America/Los Angeles GMT -7)
StatusConfirmed
Magnitude5.1
Depth30.9 km
Epicenter latitude / longitude40.3235°N / 124.4255°W North Pacific Ocean, California, United States
Antipode40.3235°S / 55.5745°E
Shaking intensityWeak shaking
Felt149 reports
Primary data sourceUSGS (United States Geological Survey)
Nearest volcanoClear Lake (211 km / 131 mi)
Weather at epicenter at time of quakeClear Sky 12.9°C (55 F), humidity: 93%, wind: 11 m/s (21 kts) from N
Estimated seismic energy released2.8 x 1012 joules (783 megawatt hours, equivalent to 674 tons of TNT) | about seismic energy
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Nearby places

Distance Place Max. shaking intensity(*) Region Country
31 km (19 mi)
NNE of epicenter
Ferndale
(pop: 1,370)
IV
Light
Humboldt, California
33 km (21 mi)
NE of epicenter
Rio Dell
(pop: 3,390)
IV
Light
Humboldt, California
38 km (24 mi)
NE of epicenter
Fortuna
(pop: 12,000)
IV
Light
Humboldt, California
56 km (35 mi)
ESE of epicenter
Redway
(pop: 1,230)
IV
Light
Humboldt, California
58 km (36 mi)
NNE of epicenter
Eureka
(pop: 27,000)
IV
Light
Humboldt, California
65 km (41 mi)
NNE of epicenter
Bayside
(pop: 17,100)
IV
Light
Humboldt, California
67 km (42 mi)
NNE of epicenter
Arcata
(pop: 17,800)
IV
Light
Humboldt, California
75 km (46 mi)
NNE of epicenter
McKinleyville
(pop: 15,200)
III
Weak
Humboldt, California
175 km (108 mi)
E of epicenter
Redding
(pop: 91,600)
III
Weak
Shasta, California
241 km (150 mi)
SE of epicenter
Windsor
(pop: 27,500)
II
Very weak
Sonoma, California
Notes:
(*) Shaking intensity according to the Modified Mercalli Intensity Scale (MMI) and estimated using seismic models.

Compare Quake Data

Data for the same earthquake as reported by different agencies

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.
Mag Depth Time GMT Epicenter Agency
5.1 31 km (19 mi) 2021-07-18 06:46:12 12km W of Petrolia, CA USGS (United States Geological Survey)
4.0 9 km (5.6 mi) 2021-07-18 06:46:16 20 Km SSW of Scotia, California
17 km (10.6 mi) epicenter difference with USGS
USGS (United States Geological Survey)
5.1 60 km (37 mi) 2021-07-18 06:46:17 NORTHERN CALIFORNIA
27 km (17 mi) epicenter difference with USGS
EMSC (European-Mediterranean Seismological Centre)
4.9 10 km (6.2 mi) (*) 2021-07-18 06:46:10 Near Coast of N. California
23 km (15 mi) epicenter difference with USGS
GFZ (German Research Centre for Geosciences)
Notes:
(*) A depth given as 10 km often means that the the depth of the quake could not determined with sufficient accuracy.

Seismograms

Seismic station: Columbia College, Columbia, CA, USA (CMB/BK network) | Distance from quake: 431 km / 268 mi | Show on map | Station Info
Seismic station Columbia College, Columbia, CA, USA: vertical movement plot around time of quake (source: IRIS/BUD)
Seismogram (vertical component) around time of quake. Thin dotted red line indicates time of quake. Seismic waves arrive some time later, depending on distance. Bandpass filter applied: 0.1-10.0 Hz. Source: IRIS Buffer of Uniform Data (BUD) webtool
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User-reports for this quake (165)

User reports estimate the perceived ground shaking intensity according to the MMI (Modified Mercalli Intensity) scale.
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95542 / Moderate shaking (MMI V) / rattling, vibrating / 5-10 s : Was sitting outside and saw the roofline roll on a 60 ft. Single level house. | 12 users found this interesting.  
Chico, CA (230.2 km ESE of epicenter) [Map] / Very weak shaking (MMI II) / rattling, vibrating / 5-10 s : My husband and I were sitting in the living room watching a movie and both felt a weak vibration/shaking of the furniture. It lasted long enough for us to realize it was a quake. Nothing was knocked over, but the cords on the fans were swaying. | 6 users found this interesting.  
McKinleyville (73.3 km NNE of epicenter) [Map] / Very weak shaking (MMI II) / rattling, vibrating / 1-2 s : Lying in bed. Felt like a ferret was humping the foot of my bed. Extremely light, few seconds. | 7 users found this interesting.  
Mendocino ca / Light shaking (MMI IV) / single lateral shake / 5-10 s : House creaked; bed shook a little for a few seconds; nothing fell/shifted position. I heard something thump or scrape outside the house just before I felt the shaking. | 6 users found this interesting.  
  • In the last year or so I've noticed a lot of people saying these quakes and tremours sound different or a boom is heard. It seems like something different could be haplening beneath the ground compared to typical quakes of the past maybe.
Laytonville (107.6 km SE of epicenter) [Map] / Light shaking (MMI IV) / vibration and rolling / 1-2 minutes : After the initial rolling jolts, It lingered on, gently for about 3 minutes. It tapered off. Dog was concerned. | 5 users found this interesting.  
Shasta-Keswick, CA (169.6 km ENE of epicenter) [Map] / Light shaking (MMI IV) / horizontal (sideways) swinging / 5-10 s : Sitting on couch watching a movie and I thought the dog was leaning against the couch scratching but then I saw my dog was laying down on the other side of the room. Shaking continued for several seconds, perhaps 5-7. | 5 users found this interesting.  
Chico, Butte, California (224.7 km ESE of epicenter) [Map] / Weak shaking (MMI III) / horizontal (sideways) swinging / 1-2 s : Windows creaked first then I felt myself swaying horizontally. Lights and my crystals in my windows were swaying. | 5 users found this interesting.  
Orland, Ca, / Very weak shaking (MMI II) / 2-5 s : It felt like someone had pushed the car. Like a wave motions. But, there was no one there & I'm a Californian used to earthquakes so I looked up USGS. It wasn't recorded, yet. | 5 users found this interesting.  
Chico Ca (224.7 km ESE of epicenter) [Map] / Weak shaking (MMI III) / horizontal (sideways) swinging / 2-5 s : Windows creaking first. Then the swaying started. Crystals in my windows swayed back and forth and I felt light headed | 4 users found this interesting.  
Little River, California (133.9 km SE of epicenter) [Map] / Moderate shaking (MMI V) / rattling, vibrating / 5-10 s : I heard a noise; the house creaked and shook and my bed, on a wooden stand, shimmied significantly. It stopped quickly, but I was alarmed. am more than 3 miles inland from the Coast Highway # 1 in Little River, 95456 zip code. | 3 users found this interesting.  
Paradise ca (252 km E of epicenter) [Map] / Light shaking (MMI IV) / horizontal (sideways) swinging / 20-30 s : My rv started rocking back and forth, thought it was the wind at first, but when I went outside it was calm. | 3 users found this interesting.  
miranda ca / Very weak shaking (MMI II) / rattling, vibrating / 2-5 s : creaking thump short pause then 2 to 4 second heavy shaking and rocking strongest in a couple years | 5 users found this interesting.  
Comptche Ukiah Rd, Mendocino Ca / Very weak shaking (MMI II) / rattling, vibrating / 5-10 s : Totally thought my big cat was underneath my bed | 5 users found this interesting.  
Shelter Cove CA 95588 (45 km SE of epicenter) [Map] / Light shaking (MMI IV) / rattling, vibrating / 5-10 s : Loud rumbling. Hard shaking and rattling. Don’t know if felt outdoors but most likely. My dogs didn’t make any noise but we aren’t in the same room so don’t know their response. | 2 users found this interesting.  
Salmon Creek watershed near Myers Flat seemed to l / Moderate shaking (MMI V) / 2-5 s : woke me from my sleep had to wait a few seconds before I got out of bed and checked the house. | 4 users found this interesting.  
Uk / not felt : This quake is being ignored by the seismograph on YouTube... concerning | 4 users found this interesting.  
  • From what I have seen quite a number of quakes are not showing up on the official Twitter or Youtube trackers. This doesn't sound good to me. People need as much infor as possibke as Cali has been very active along most of it state boundaries and coast in last 2-3 years. People need to be told what's happening.
  • Possibly due to lack of intensity on land?? I've heard about it in little old New Zealand....
Eureka / Very weak shaking (MMI II) / 5-10 s : I was laying in bed and felt the bed moving, like a rolling sensation. | 4 users found this interesting.  
Hayward California (362.9 km SE of epicenter) [Map] / not felt : Im in Hayward California didn't feel anything | 3 users found this interesting. (reported through our app)  
31 km of Covelo, Mendocino, California (87.6 km ESE of epicenter) [Map] / Light shaking (MMI IV) / horizontal (sideways) swinging / 1-2 s : Camping and was woken up by a jolt and then rocking | 3 users found this interesting.  
95562 (23.9 km E of epicenter) [Map] / Light shaking (MMI IV) / horizontal (sideways) swinging / 20-30 s : Seemed like it last awhile | 3 users found this interesting.  
Corning (192.9 km E of epicenter) [Map] / Very weak shaking (MMI II) / horizontal (sideways) swinging / very short : Home felt like it was shaking side to side | 3 users found this interesting. (reported through our app)  
  • How could they ignore it? That's their job.... What could this possibly mean?
  • How could they ignore it? That's their job.... What could this possibly mean?
  • This one was ignored by the live earthquake tracker on YouTube..
Fort bragg,ca / Very weak shaking (MMI II) / rattling, vibrating : I was upstairs I felt an initial jolt then just shaking,felt like it lasted awhile. We had a small one at northstar winery fault line at xmas few years back 2. Something. That one made the xmas tree rattle shortly. I remember prima loma earthqu | 2 users found this interesting.  
Ukiah,CA / Light shaking (MMI IV) / rattling, vibrating / very short : Rattle and vibration on walls on the second floor, bottom floor felt like someone slammed against the wall. | 2 users found this interesting.  
Westport, CA (125.3 km SSE of epicenter) [Map] / Weak shaking (MMI III) / horizontal (sideways) swinging / 10-15 s : Initial side to side shaking jolt followed by weaker shaking; slight rumble sound; objects near by rattled; | One user found this interesting.  
Eel rock, Ca. / Moderate shaking (MMI V) / horizontal (sideways) swinging / 15-20 s : 1 strong jolt followed by several seconds of quite strong shaking. 15–20seconds and it was over. | 3 users found this interesting.  
Willits, California / Light shaking (MMI IV) / horizontal (sideways) swinging / 20-30 s : The shake intensity was somewhat mild. The floor was going back and forth about 20 to 30 seconds | 3 users found this interesting.  
204 McKinley St Ft Bragg, CA. / Very weak shaking (MMI II) / single lateral shake / very short : A single jolt sideways, bed moved a bit to the South! Paintings made crooked on the wall! | 3 users found this interesting.  
Laytonville, ca / Light shaking (MMI IV) / very short : Abrupt jerk and woke us both up from sleep | 3 users found this interesting.  
Near Lolita corner of Singley Hill Rd. & Bear Rive (39.9 km NNE of epicenter) [Map] / Light shaking (MMI IV) / both vertical and horizontal swinging / 2-5 s : Three four bumps. Lying in bed and it felt like someone was shaking the bed a bit | 2 users found this interesting.  
Fruit land ridge (53.3 km E of epicenter) [Map] / Light shaking (MMI IV) / horizontal (sideways) swinging / 5-10 s : Light back and forth kind of scaryish | 2 users found this interesting.  
Mendocino (125.1 km SSE of epicenter) [Map] / Light shaking (MMI IV) / horizontal (sideways) swinging / 5-10 s : Moderate shaking without anything falling or breaking | 2 users found this interesting.  
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Aftershocks

[More info]

Recorded aftershocks, latest first (30 quakes)

Date and Time GMTMag
Depth
RegionDetails
Sep 13, 2021 02:20
2 years ago
2.4

18 km
18km WSW of Petrolia, CAMore
Sep 12, 2021 13:54
2 years ago
2.5

31 km
8km SW of Petrolia, CAMore
Sep 11, 2021 03:00
2 years ago
2.4

21 km
23km WNW of Petrolia, CAMore
Sep 10, 2021 17:06
2 years ago
2.2

25 km
5km WSW of Petrolia, CAMore
Sep 10, 2021 00:03
2 years ago
2.2

31 km
8km WSW of Petrolia, CAMore
Sep 9, 2021 21:57
2 years ago - felt
4.5

33 km
38 mi S of Eureka, Humboldt County, California, USAMore
Sep 3, 2021 22:18
2 years ago
2.3

28 km
7km W of Petrolia, CAMore
Sep 2, 2021 23:59
2 years ago
2.4

17 km
8km W of Petrolia, CAMore
Aug 31, 2021 08:01
2 years ago - felt
4.0

32 km
38 mi S of Eureka, Humboldt County, California, USAMore
Aug 30, 2021 07:17
2 years ago
2.4

19 km
22km NW of Petrolia, CAMore
Aug 25, 2021 08:42
2 years ago
2.1

23 km
2km W of Petrolia, CAMore
Aug 20, 2021 18:01
2 years ago
3.2

24 km
21 mi SW of Fortuna, Humboldt County, California, USAMore
Aug 15, 2021 08:14
2 years ago
2.0

6.8 km
30km W of Petrolia, CAMore
Aug 13, 2021 22:40
2 years ago
2.2

29 km
8km WSW of Petrolia, CAMore
Aug 13, 2021 19:40
2 years ago
2.0

22 km
8km NW of Petrolia, CAMore
Aug 13, 2021 04:11
2 years ago
2.4

24 km
2km WSW of Petrolia, CAMore
Aug 12, 2021 08:03
2 years ago
2.8

27 km
North Pacific Ocean, 39 mi SW of Eureka, Humboldt County, California, USAMore
Aug 10, 2021 02:03
2 years ago
2.8

26 km
34 mi S of Eureka, Humboldt County, California, USAMore
Aug 8, 2021 10:40
2 years ago - felt
3.4

24 km
21 mi SW of Fortuna, Humboldt County, California, USAMore
Aug 7, 2021 23:43
2 years ago
2.2

29 km
5km WSW of Petrolia, CAMore
Aug 6, 2021 09:56
2 years ago
2.2

28 km
6km ENE of Petrolia, CAMore
Aug 2, 2021 06:34
2 years ago
2.3

24 km
2km W of Petrolia, CAMore
Jul 28, 2021 09:43
2 years ago
2.3

18 km
21km W of Petrolia, CAMore
Jul 28, 2021 06:52
2 years ago
2.5

27 km
6km N of Petrolia, CAMore
Jul 25, 2021 23:20
2 years ago
2.9

33 km
North Pacific Ocean, 37 mi SW of Eureka, Humboldt County, California, USAMore
Jul 24, 2021 23:06
2 years ago
2.9

24 km
36 mi S of Eureka, Humboldt County, California, USAMore
Jul 23, 2021 20:09
2 years ago
2.7

26 km
34 mi S of Eureka, Humboldt County, California, USAMore
Jul 21, 2021 10:05
2 years ago - felt
4.4

35 km
39 mi S of Eureka, Humboldt County, California, USAMore
Jul 18, 2021 07:38
2 years ago
2.2

31 km
4km SW of Petrolia, CAMore
Jul 18, 2021 07:05
2 years ago
2.4

29 km
9km W of Petrolia, CAMore

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