On Wednesday Evening a Shallow M4.4 Earthquake struck near Eureka in The United States.

Written by Earthquakelist.org on October 24th, 2024. Last updated November 21st, 2024.

A shallow M4.4 earthquake struck under land 37 miles from Eureka in The United States just before midnight of Wednesday October 23rd, 2024. The USGS has indicated there is a potential risk at tsunami's following this earthquake.

Earthquake Summary

The earthquake struck on land in The United States, 37 miles (59 km) south of Eureka in California. The center of this earthquake had a very shallow depth of 6 km. Shallow earthquakes usually have a larger impact than earthquakes deep in the earth.

Date and Time:	Oct 23, 2024 11:58PM (Los Angeles Time) - Oct 24, 2024 06:58 Universal Time.
Location:	37 mi south of Eureka, California, The United States. Coordinates 40°16'46"N 124°17'43"W.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 4.4 Detected by 59 stations. Maximum Error Range ±0.2 .
Depth:	6 mi (10 km) A very shallow depth.
Max. Intensity:	V Moderate On the Modified Mercalli Scale.
Tsunami Risk:	Potential tsunami risk The USGS has indicated there is a potential risk at tsunami's following this earthquake. Always stay cautious - More info here.

Potential tsunami risk

DISCLAIMER: We strongly suggest to closely monitor advice from local authorities with regards to tsunami risks. Our analysis is based on automatically collected data from external sources, and these might contain mistakes. In addition, earthquakes can cause landslides that may lead to a tsunami, or be a followed by another, potentially stonger, earthquake.

There is a potential tsunami risk in the aftermath of this earthquake, immediately evacuate to higher grounds away from coastal areas and monitor advice from local authorities. The US Geographic Survey organization has indicated a potential risk for tsunami's following this earthquake.

Tsunami Risk Factors

Factor	Under Sea?	MAG-6.5 or stronger?	Shallow depth?
Explanation	Almost all tsunami's are caused by earthquakes with their epicenter under sea or very near the sea. However stay cautious in coastal areas as earthquakes on land may cause landslides into sea, potentially still causing a local tsunami.	Under MAG 6.5: Very unlikely to cause a tsunami. MAG 6.5 to 7.5: Destructive tsunami's do occur, but are uncommon. Likely to observe small sea level changes. MAG 7.6+: Earthquakes with these magnitudes might produce destructive tsunami's.	Most destructive tsunami's are caused by shallow earthquakes with a depth between 0 and 100km under the surface of the earth. Deeper tsunami's are unlikely to displace to ocean floor.
This Earthquake	This earthquake appears to have struck on land near a coastal area (3 mi from the sea).	Not this earthquake. This earthquake had a magnitude of 4.4. Earthquakes of this strength are unlikely to trigger a tsunami.	This earthquake occurred at a depth of of 6 mi (10 km). Earthquakes this shallow could trigger a tsunami.

Minimal impact predicted

Based on scientific estimates by the US Geographic Survey (USGS), the risk of high fatalities for this earthquake is classified at level GREEN (low). They expect an 65% likelyhood of between 0 and 1 fatalities, and a 96% chance that the number of fatalities falls no higher than 10.

The USGS classifies the economic impact of this earthquake at level GREEN (low). They expect an 65% likelyhood of between 0 and 1 million US Dollars in economic damage and impact, and a 96% chance that the economic impact of this earthquake falls no higher than 10 million USD.

Roughly 390 thousand people exposed to shaking

An estimated 390 thousand have been exposed to shaking (An MMI or Modified Mercalli Intensity level II or higher) as a result of this earthquake according scientific estimates published by the USGS.

An estimated 2,050 people were exposed to level IV. At this level, light shaking and likely no damage can be expected. The majority of people (roughly 570 thousand) live in an area exposed to level I, where not noticeable and no damage is expected.

People	MMI Level	Shaking	Damage
571,900	I	Not noticable	None
306,100	II	Very weak	None
78,100	III	Weak	Probably none
2,050	IV	Light	Likely none
0	V	Moderate	Very light
0	VI	Strong	Light
0	VII	Very Strong	Moderate
0	VIII	Severe	Moderate to heavy
0	IX	Violent	Heavy
0	X	Extreme	Very heavy

Nearby towns and cities

This earthquake may have been felt in The United States . Located 37 miles (59 km) south of the epicenter of this earthquake, Eureka (California, The United States) is the nearest significant population center. The intensity of shaking and damage in Eureka is estimated to be around level III on the Modified Mercalli Intensity scale (weak shaking, probably no damage).

Multiple major population centers exist within 300km of the earthquake that struck today. Santa Rosa is located 153 mi to the south-east (intensity unknown, possibly low). Chico is located 135 mi to the east-southeast (intensity unknown, possibly low). Vallejo is located 186 mi to the south-east (intensity unknown, possibly low).

The table below provides an overview of all places in proximity of today's earthquake. Where available, the estimated intensity on the Modified Mercalli Intensity Scale in each place is included. Places where this information is omitted likely experienced little impact.

Overview of nearby places

Cities and Towns around the epicenter of this earthquake.
Distance	Place	Intensity (MMI)
37 mi (59 km) N from epicenter	Eureka California, The United States.	III Weak
41 mi (66 km) NNE from epicenter	Bayside California, The United States.	II Weak
42 mi (68 km) NNE from epicenter	Arcata California, The United States.	II Weak
47 mi (76 km) NNE from epicenter	McKinleyville California, The United States.	II Weak
97 mi (156 km) SE from epicenter	Ukiah California, The United States.	I Not felt
103 mi (165 km) ENE from epicenter	Redding California, The United States.	I Not felt
127 mi (205 km) SE from epicenter	Clearlake California, The United States.	I Not felt
135 mi (218 km) ESE from epicenter	Chico California, The United States.
144 mi (231 km) SE from epicenter	Windsor California, The United States.	I Not felt
146 mi (235 km) ESE from epicenter	Paradise California, The United States.
153 mi (246 km) SE from epicenter	Santa Rosa California, The United States.
155 mi (249 km) ESE from epicenter	Oroville California, The United States.
156 mi (251 km) NNE from epicenter	Ashland Oregon, The United States.
157 mi (253 km) NNE from epicenter	Grants Pass Oregon, The United States.
159 mi (256 km) SSE from epicenter	Rohnert Park California, The United States.
160 mi (257 km) NNE from epicenter	Medford Oregon, The United States.
162 mi (260 km) NNE from epicenter	Central Point Oregon, The United States.
162 mi (261 km) ESE from epicenter	South Yuba City California, The United States.
163 mi (262 km) ESE from epicenter	Yuba City California, The United States.
166 mi (267 km) ESE from epicenter	Linda California, The United States.
167 mi (269 km) SSE from epicenter	Petaluma California, The United States.
174 mi (280 km) SE from epicenter	Napa California, The United States.
174 mi (280 km) SE from epicenter	Woodland California, The United States.
176 mi (284 km) SSE from epicenter	Novato California, The United States.
181 mi (292 km) SE from epicenter	Davis California, The United States.
181 mi (292 km) SE from epicenter	Vacaville California, The United States.
181 mi (292 km) SE from epicenter	American Canyon California, The United States.
183 mi (294 km) SE from epicenter	Dixon California, The United States.
185 mi (298 km) SSE from epicenter	San Rafael California, The United States.
185 mi (298 km) SE from epicenter	Fairfield California, The United States.
186 mi (299 km) SE from epicenter	Suisun California, The United States.
186 mi (299 km) SE from epicenter	Vallejo California, The United States.
186 mi (300 km) ESE from epicenter	Lincoln California, The United States.

Earthquake Intensity Map

The graph below overlays a map of the region around the epicenter with earthquake intensity data provided by the US Geographic Survey. The highest intensity level detected for this earthquake is V.

I Not felt

II Weak

III Weak

IV Light

V Moderate

VI Strong

VII Very Strong

VIII Severe

IX Violent

X Extreme

Earthquake Intensity Map based on Shakemap Data provided by USGS.

3 Aftershocks detected

Since this main shock, 3 smaller aftershocks were detected. A 3.9 magnitude earthquake hit 1 min later 0.4 mi (0.6 km) north-northeast of this earthquake.

This main shock was prefaced by 2 smaller foreshocks. Roughly 41 mins before this earthquake, a foreshock measuring MAG-4 was detected nearby this earthquake.

Overview of foreshocks and aftershocks

Detected MAG2.5+ earthquakes within within 100km (62 mi), that occurred in the three days before and after the main shock.
Classification	Magnitude	When	Where
Foreshock	M 3.7	1 hr earlier Oct 23, 2024 10:56PM (Los Angeles Time)	0.8 mi (1.3 km) ENE from Main Shock.
Foreshock	M 4.0	41 mins earlier Oct 23, 2024 11:18PM (Los Angeles Time)	0.4 mi (0.7 km) SE from Main Shock.
Main Shock This Earthquake	M 4.4	Oct 23, 2024 11:58PM (Los Angeles Time)	-
Aftershock	M 3.9	1 min later Oct 23, 2024 11:59PM (Los Angeles Time)	0.4 mi (0.6 km) NNE from Main Shock.
Aftershock	M 2.8	7 mins later Oct 24, 2024 12:05AM (Los Angeles Time)	0.6 mi (1 km) ENE from Main Shock.
Aftershock	M 3.4	2 days later Oct 26, 2024 02:34AM (Los Angeles Time)	50 mi (80 km) W from Main Shock.

More earthquakes coming?

The risk of aftershocks decreases rapidly over time. Usually, aftershocks are at least one order of magnitude lower than a main shock.

The chance that a significant earthquake like this one is followed by an even larger earthquake is not so large. On average, scientists estimate a 94% chance that a major earthquake will not be followed by an even larger one. It is still adviced to be aware of this risk

Read: How to Stay Safe during an Earthquake (cdc.gov).

Earthquakes like this happen often in the region

Earthquakes of this strength are very common in the region. This is the strongest earthquake to hit since September 28th, 2024, when a 4.5 magnitude earthquake hit 173 mi (278 km) further northwest. An even stronger magnitude 6.6 earthquake struck on December 8th, 2016.

In total, 105 earthquakes with a magnitude of 4.4 or higher have been registered within 300km (186 mi) of this epicenter in the past 10 years. This comes down to an average of once every month.

Sources

Last updated 21/11/24 01:38 (). As more information on this earthquake becomes available this article will be updated. This article is automatically composed based on data originating from multiple sources.