On Saturday Evening a Shallow M5.6 Earthquake struck in the Coral Sea near Port-Vila (Vanuatu).

Written by Earthquakelist.org on November 11th, 2023. Last updated December 9th, 2023.

A shallow and significant MAG-5.6 earthquake struck in the Coral Sea 30 kilometer from Port-Vila, Vanuatu just before midnight of Saturday November 11th, 2023. Shaking may have been felt by a total of 190 thousand people.

Earthquake Summary

This earthquake hit under water in the Coral Sea, right off the coast of Vanuatu (12 mi offshore), 30 kilometer southwest of Port-Vila in Shefa. The center of this earthquake had a very shallow depth of 23 km. Shallow earthquakes usually have a larger impact than earthquakes deep in the earth.

Date and Time:	Nov 11, 2023 11:35PM (Efate Time) - Nov 11, 2023 12:35 Universal Time.
Location:	30 km SW of Port-Vila, Shefa, Vanuatu. Coordinates 17°54'32"S 168°6'5"E.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 5.6 Detected by 39 stations. Maximum Error Range ±0.05 .
Depth:	23 km (14 mi) A very shallow depth.
Max. Intensity:	V Moderate On the Modified Mercalli Scale.
Tsunami Risk:	Low tsunami risk Earthquakes under MAG-6.5 do not usually cause tsunami's. Always stay cautious - More info here.

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 190 thousand people exposed to shaking

An estimated 190 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.

Moderate shaking and very light damage may have been experienced by an estimated 350 people. At V, it is the highest MMI level this earthquake has caused. Intensity level III was experienced by the majority of people (around 100 thousand). In their region, weak shaking and probably no damage can be expected. All exposure to shaking was within the borders of Vanuatu .

People	MMI Level	Shaking	Damage
0	I	Not noticable	None
1,660	II	Very weak	None
97,760	III	Weak	Probably none
94,940	IV	Light	Likely none
350	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 Vanuatu . Located 30 kilometer (19 mi) southwest of the epicenter of this earthquake, Port-Vila (Shefa, Vanuatu) is the nearest significant population center. The intensity of shaking and damage in Port-Vila is estimated to be around level IV on the Modified Mercalli Intensity scale (light shaking, likely no damage).

Overview of nearby places

Cities and Towns around the epicenter of this earthquake.
Distance	Place	Intensity (MMI)
30 km (19 mi) NE from epicenter	Port-Vila Shefa, Vanuatu.	IV Light

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.

Shaking reported by 31 people

People that feel an earthquake may report their experience to the US Geographic Survey. Currently, 31 people have reported shaking in one place in Vanuatu.We keep updating this article as more ground reports become available. You may report that you felt this earthquake here.

Places with most reports:

Vila, Shefa, Vanuatu: 31 people.

2 Aftershocks detected

Since this main shock, 2 smaller aftershocks were detected. At a distance of 9 km (6 mi) southwest of this earthquake, an aftershock struck 13 mins later. It measured a magnitude of 4.3

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
Main Shock This Earthquake	M 5.6	Nov 11, 2023 11:35PM (Efate Time)	-
Aftershock	M 4.3	13 mins later Nov 11, 2023 11:48PM (Efate Time)	9 km (6 mi) SW from Main Shock.
Aftershock	M 4.0	19 mins later Nov 11, 2023 11:54PM (Efate Time)	7 km (4 mi) W from Main Shock.

More earthquakes coming?

Aftershocks are usually at least 1 order of magnitude less strong than main shocks. The more time passes, the smaller the chance and likely strength of any potential aftershocks.

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 October 29th, 2023, when a 6 magnitude earthquake hit 180 km (112 mi) further south-southeast. An even stronger magnitude 7 earthquake struck on April 28th, 2016.

In total, 57 earthquakes with a magnitude of 5.6 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.

Low 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.

Based on early data it appears this earthquake was not strong enough (lower than MAG-6.5) to be likely to cause destructive tsunami's. However this earthquake appeared to have hit at a shallow depth under sea, so stay cautious and monitor advice from local authorities.

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 under the sea.	Not this earthquake. This earthquake had a magnitude of 5.6. Earthquakes of this strength are unlikely to trigger a tsunami.	This earthquake occurred at a depth of of 23 km (14 mi). Earthquakes this shallow could trigger a tsunami.

Sources

Last updated 09/12/23 01:28 (). 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.