Shallow M5.1 FORESHOCK hit 88mi from Juneau in The United States on Friday Evening.

Written by Earthquakelist.org on October 28th, 2023. Last updated December 8th, 2023.

A shallow and significant MAG-5.1 foreshock struck under land 88 miles from Juneau in The United States in the evening of Friday October 27th, 2023. The USGS has indicated there is a potential risk at tsunami's following this earthquake. Another country near the epicenter is Canada.

Earthquake Summary

The earthquake struck on land in The United States, 88 miles (142 km) northwest of Juneau in Alaska. The center of this earthquake had a very shallow depth of 4 km. Shallow earthquakes usually have a larger impact than earthquakes deep in the earth.

Date and Time:	Oct 27, 2023 07:01PM (Juneau Time) - Oct 28, 2023 03:01 Universal Time.
Location:	88 mi NW of Juneau, Alaska, The United States. Coordinates 59°1'6"N 136°27'35"W.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 5.1 Detected by 18 stations. Maximum Error Range ±0.04 .
Depth:	4 mi (7 km) A very shallow depth.
Max. Intensity:	VI Strong 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 (4 mi from the sea).	Not this earthquake. This earthquake had a magnitude of 5.1. Earthquakes of this strength are unlikely to trigger a tsunami.	This earthquake occurred at a depth of of 4 mi (7 km). Earthquakes this shallow could trigger a tsunami.

Nearby towns and cities

2 countries can be found within 300km of the epicenter of this earthquake: The United States and Canada .

Juneau in Alaska, The United States is the nearest significant place from the epicenter. The earthquake occurred 88 miles (142 km) northwest of Juneau. The intensity of shaking and damage in Juneau is estimated to be around level III on the Modified Mercalli Intensity scale (weak shaking, probably no damage).

Overview of nearby places

Cities and Towns around the epicenter of this earthquake.
Distance	Place	Intensity (MMI)
88 mi (142 km) SE from epicenter	Juneau Alaska, The United States.	III Weak
204 km (127 mi) NNE from epicenter	Whitehorse Yukon, Canada.	II Weak

Earthquake Intensity Map

The intensity in shaking and damage by this earthquake is illustrated through the map below. The highest intensity measured for this earthquake is VI.

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.

Shaking reported by 10 people

People that feel an earthquake may report their experience to the US Geographic Survey. Currently, 10 people have reported shaking in one place in Canada.We keep updating this article as more ground reports become available. You may report that you felt this earthquake here.

Places with most reports:

Whitehorse, Yukon, Canada: 10 people.

This is likely a foreshock

This earthquake was followed by a stronger MAG-5.3 earthquake, classifying this earthquake as a foreshock.

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 This Earthquake	M 5.1	42 mins earlier Oct 27, 2023 07:01PM (Juneau Time)	3 mi (5 km) ENE from Main Shock.
Main Shock	M 5.3	Oct 27, 2023 07:44PM (Juneau Time)	-
Aftershock	M 2.6	28 mins later Oct 27, 2023 08:11PM (Juneau Time)	2.7 mi (4 km) ENE from Main Shock.
Aftershock	M 3.5	1 hr later Oct 27, 2023 09:11PM (Juneau Time)	3 mi (5 km) ESE from Main Shock.
Aftershock	M 3.0	2 hrs later Oct 27, 2023 10:00PM (Juneau Time)	3 mi (5 km) E from Main Shock.
Aftershock	M 2.5	3 hrs later Oct 27, 2023 10:25PM (Juneau Time)	4 mi (6 km) NE from Main Shock.
Aftershock	M 2.7	17 hrs later Oct 28, 2023 12:33PM (Juneau Time)	3 mi (5 km) NE from Main Shock.
Aftershock	M 2.9	17 hrs later Oct 28, 2023 12:33PM (Juneau Time)	4 mi (7 km) ENE from Main Shock.
Aftershock	M 3.1	22 hrs later Oct 28, 2023 05:18PM (Juneau Time)	2.2 mi (4 km) ENE from Main Shock.

More earthquakes coming?

Earthquakes can create aftershocks. These are generally at least 1 magnitude lower than any main shock, and as time passes the chance and strength of aftershocks decreases.

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 are common in the region

Earthquakes of this strength occur quite regularly in the region. This is the strongest earthquake to hit since January 8th, 2022, when a 5.2 magnitude earthquake hit 171 mi (275 km) further west-northwest. An even stronger magnitude 6.3 earthquake struck on May 1st, 2017.

In total, 9 earthquakes with a magnitude of 5.1 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 year.

Sources

Last updated 08/12/23 03:38 (). 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.