Significant M5.4 FORESHOCK struck on Tuesday Evening in the South Pacific Ocean 160km from Honiara (Solomon Islands).

Written by Earthquakelist.org on November 7th, 2023. Last updated December 8th, 2023.

A significant Magnitude 5.4 foreshock struck in the South Pacific Ocean 160 kilometer from Honiara, Solomon Islands in the evening of Tuesday November 7th, 2023. Roughly 490 thousand people may have felt this earthquake.

Earthquake Summary

This earthquake hit under water in the South Pacific Ocean, right off the coast of Solomon Islands (6 mi offshore), 160 kilometer north-east of Honiara. The center of this earthquake had a quite shallow depth of 44 km. Shallow earthquakes usually have a larger impact than earthquakes deep in the earth.

Date and Time:	Nov 7, 2023 18:30 (Guadalcanal Time) - Nov 7, 2023 07:30 Universal Time.
Location:	160 km NE of Honiara, Solomon Islands. Coordinates 8°20'16"S 160°53'24"E.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 5.4 Detected by 17 stations. Maximum Error Range ±0.075 .
Depth:	44 km (27 mi) A quite 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 490 thousand people exposed to shaking

This earthquake may have been felt by around 490 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.

An estimated 260 people were exposed to level V. At this level, moderate shaking and very light damage can be expected. Intensity level III was experienced by the majority of people (around 320 thousand). In their region, weak shaking and probably no damage can be expected. All exposure to shaking was within the borders of Solomon Islands .

People	MMI Level	Shaking	Damage
0	I	Not noticable	None
0	II	Very weak	None
323,800	III	Weak	Probably none
162,400	IV	Light	Likely none
260	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 Solomon Islands . Honiara in Honiara, Solomon Islands is the nearest significant place from the epicenter. The earthquake occurred 160 kilometer (99 mi) north-east of Honiara. The intensity of shaking and damage in Honiara 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)
160 km (99 mi) SW from epicenter	Honiara Honiara, Solomon Islands.	III Weak

Earthquake Intensity Map

The maximum intensity (MMI Scale) caused by this earthquake is V. The map below shows in which areas this earthquake was the most and least impactful. It is based on data from the US Geographic Survey.

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.

This is likely a foreshock

This earthquake was followed by a stronger MAG-5.5 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	M 4.9	2 hrs earlier Nov 7, 2023 16:49 (Guadalcanal Time)	10 km (6 mi) N from Main Shock.
Foreshock This Earthquake	M 5.4	16 mins earlier Nov 7, 2023 18:30 (Guadalcanal Time)	11 km (7 mi) E from Main Shock.
Main Shock	M 5.5	Nov 7, 2023 18:47 (Guadalcanal Time)	-
Aftershock	M 4.7	2 hrs later Nov 7, 2023 21:13 (Guadalcanal Time)	24 km (15 mi) E from Main Shock.
Aftershock	M 4.3	10 hrs later Nov 8, 2023 04:59 (Guadalcanal Time)	28 km (17 mi) ENE 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 October 28th, 2023, when a 5.5 magnitude earthquake hit 215 km (134 mi) further south-southeast. An even stronger magnitude 7.8 earthquake struck on December 8th, 2016.

In total, 62 earthquakes with a magnitude of 5.4 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 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 5.4. Earthquakes of this strength are unlikely to trigger a tsunami.	This earthquake occurred at a depth of of 44 km (27 mi). Earthquakes this shallow could trigger a tsunami.

Sources

Last updated 08/12/23 11:08 (). 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.