M4.6 Earthquake hit 121mi from Anchorage in The United States on Sunday Night.

Written by Earthquakelist.org on September 1st, 2024. Last updated September 16th, 2024.

In the early morning of Sunday September 1st, 2024, a M4.6 earthquake hit under land 121 miles from Anchorage in The United States. 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, 121 miles (195 km) south-southwest of Anchorage in Alaska. The center of this earthquake had a quite shallow depth of 30 km. Shallow earthquakes usually have a larger impact than earthquakes deep in the earth.

Date and Time:	Sep 1, 2024 05:20AM (Anchorage Time) - Sep 1, 2024 13:20 Universal Time.
Location:	121 mi SSW of Anchorage, Alaska, The United States. Coordinates 59°39'18"N 151°31'17"W.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 4.6 Detected by 38 stations. Maximum Error Range ±0.031 .
Depth:	30 mi (48 km) A quite shallow depth.
Max. Intensity:	IV Light 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 (1 mi from the sea).	Not this earthquake. This earthquake had a magnitude of 4.6. Earthquakes of this strength are unlikely to trigger a tsunami.	This earthquake occurred at a depth of of 30 mi (48 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 69% likelyhood of between 0 and 1 fatalities, and a 98% 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 330 thousand people exposed to shaking

This earthquake may have been felt by around 330 thousand people. That is the expected population size of the area exposed to a level of shaking of II or higher on the Modified Mercalli scale according to the USGS.

The highest earthquake impact level for this earthquake is III, which corresponds with weak shaking and probably no damage. Roughly 55,470 people are expected to be exposed to this level. The majority of people (roughly 270 thousand) live in an area exposed to level II, where very weak shaking and no damage is expected.

People	MMI Level	Shaking	Damage
46,870	I	Not noticable	None
273,800	II	Very weak	None
55,470	III	Weak	Probably none
0	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 . Anchorage in Alaska, The United States is the nearest significant place from the epicenter. The earthquake occurred 121 miles (195 km) south-southwest of Anchorage. The intensity of shaking and damage in Anchorage is estimated to be around level I on the Modified Mercalli Intensity scale (not noticeable, no damage).

Overview of nearby places

Cities and Towns around the epicenter of this earthquake.
Distance	Place	Intensity (MMI)
121 mi (195 km) NNE from epicenter	Anchorage Alaska, The United States.	I Not felt
133 mi (214 km) NNE from epicenter	Eagle River Alaska, The United States.	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 IV.

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.

Aftershocks detected

Since this main shock, 1 smaller aftershock was detected. At a distance of 49 mi (79 km) north-east of this earthquake, an aftershock struck 1 day later. It measured a magnitude of 2.9

In the days before this main shock, 2 smaller foreshocks were detected. Nearby this earthquake a foreshock struck 1 day earlier. It measured a magnitude of 3.7

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 2.7	3 days earlier Aug 29, 2024 05:49AM (Anchorage Time)	56 mi (90 km) WNW from Main Shock.
Foreshock	M 3.7	1 day earlier Aug 30, 2024 11:49PM (Anchorage Time)	13 mi (20 km) NNE from Main Shock.
Main Shock This Earthquake	M 4.6	Sep 1, 2024 05:20AM (Anchorage Time)	-
Aftershock	M 2.9	1 day later Sep 2, 2024 01:29PM (Anchorage Time)	49 mi (79 km) NE 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 May 11th, 2024, when a 4.8 magnitude earthquake hit 48 mi (77 km) further west-northwest. An even stronger magnitude 7.1 earthquake struck on November 30th, 2018.

In total, 71 earthquakes with a magnitude of 4.6 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 2 months.

Sources

Last updated 16/09/24 00:38 (). This article contains currently available information about the earthquake and is automatically composed. We continue to update this article up to a few days after the earthquake occurred.