The University of Southampton
University of Southampton Institutional Repository

Seismicity associated with the formation of a new island in the southern Red Sea

Seismicity associated with the formation of a new island in the southern Red Sea
Seismicity associated with the formation of a new island in the southern Red Sea
Volcanic eruptions at mid-ocean ridges are rarely witnessed due to their inaccessibility, and are therefore poorly understood. Shallow waters in the Red Sea allow the study of ocean ridge related volcanism observed close to sea level. On the 18th December 2011, Yemeni fishermen witnessed a volcanic eruption in the Southern Red Sea that led to the formation of Sholan Island. Previous research efforts to constrain the dynamics of the intrusion and subsequent eruption relied primarily on interferometric synthetic aperture radar (InSAR) methods, data for which were relatively sparse. Our study integrates InSAR analysis with seismic data from Eritrea, Yemen, and Saudi Arabia to provide additional insights into the transport of magma in the crust that fed the eruption. Twenty-three earthquakes of magnitude 2.1–3.9 were located using the Oct-tree sampling algorithm. The earthquakes propagated southeastward from near Sholan Island, mainly between December 12th and December 13th. The seismicity is interpreted as being induced by emplacement of a ∼12 km-long dike. Earthquake focal mechanisms are primarily normal faulting and suggest the seismicity was caused through a combination of dike propagation and inflation. We combine these observations with new deformation modeling to constrain the location and orientation of the dike. The best-fit dike orientation that satisfies both geodetic and seismic data is NNW-SSE, parallel to the overall strike of the Red Sea. Further, the timing of the seismicity suggests the volcanic activity began as a submarine eruption on the 13th December, which became a subaerial eruption on the 18th December when the island emerged from the beneath the sea. The new intrusion and eruption along the ridge suggests seafloor spreading is active in this region.
Eyles, Jade H.W.
1799ba91-0f0e-4842-94a2-4b7c88849cf0
Illsley-Kemp, Finnigan
c24ef4cb-cbf9-4a58-af8d-da9c7eabd84d
Keir, Derek
5616f81f-bf1b-4678-a167-3160b5647c65
Ruch, Joel
859ef47c-05b5-4cf7-aa8c-dcd202701862
Jonsson, Sigurjon
439149c2-e718-4255-8884-f169c88d772d
Eyles, Jade H.W.
1799ba91-0f0e-4842-94a2-4b7c88849cf0
Illsley-Kemp, Finnigan
c24ef4cb-cbf9-4a58-af8d-da9c7eabd84d
Keir, Derek
5616f81f-bf1b-4678-a167-3160b5647c65
Ruch, Joel
859ef47c-05b5-4cf7-aa8c-dcd202701862
Jonsson, Sigurjon
439149c2-e718-4255-8884-f169c88d772d

Eyles, Jade H.W., Illsley-Kemp, Finnigan, Keir, Derek, Ruch, Joel and Jonsson, Sigurjon (2018) Seismicity associated with the formation of a new island in the southern Red Sea. Frontiers in Earth Science, 6 (141). (doi:10.3389/feart.2018.00141).

Record type: Article

Abstract

Volcanic eruptions at mid-ocean ridges are rarely witnessed due to their inaccessibility, and are therefore poorly understood. Shallow waters in the Red Sea allow the study of ocean ridge related volcanism observed close to sea level. On the 18th December 2011, Yemeni fishermen witnessed a volcanic eruption in the Southern Red Sea that led to the formation of Sholan Island. Previous research efforts to constrain the dynamics of the intrusion and subsequent eruption relied primarily on interferometric synthetic aperture radar (InSAR) methods, data for which were relatively sparse. Our study integrates InSAR analysis with seismic data from Eritrea, Yemen, and Saudi Arabia to provide additional insights into the transport of magma in the crust that fed the eruption. Twenty-three earthquakes of magnitude 2.1–3.9 were located using the Oct-tree sampling algorithm. The earthquakes propagated southeastward from near Sholan Island, mainly between December 12th and December 13th. The seismicity is interpreted as being induced by emplacement of a ∼12 km-long dike. Earthquake focal mechanisms are primarily normal faulting and suggest the seismicity was caused through a combination of dike propagation and inflation. We combine these observations with new deformation modeling to constrain the location and orientation of the dike. The best-fit dike orientation that satisfies both geodetic and seismic data is NNW-SSE, parallel to the overall strike of the Red Sea. Further, the timing of the seismicity suggests the volcanic activity began as a submarine eruption on the 13th December, which became a subaerial eruption on the 18th December when the island emerged from the beneath the sea. The new intrusion and eruption along the ridge suggests seafloor spreading is active in this region.

Text
feart-06-00141-1 - Version of Record
Available under License Creative Commons Attribution.
Download (4MB)

More information

Accepted/In Press date: 5 September 2018
e-pub ahead of print date: 24 September 2018

Identifiers

Local EPrints ID: 423568
URI: http://eprints.soton.ac.uk/id/eprint/423568
PURE UUID: 35188f73-73e6-41bd-8fd2-cd0d893d0b9f
ORCID for Finnigan Illsley-Kemp: ORCID iD orcid.org/0000-0002-7114-033X
ORCID for Derek Keir: ORCID iD orcid.org/0000-0001-8787-8446

Catalogue record

Date deposited: 26 Sep 2018 16:30
Last modified: 28 Apr 2022 02:05

Export record

Altmetrics

Contributors

Author: Jade H.W. Eyles
Author: Finnigan Illsley-Kemp ORCID iD
Author: Derek Keir ORCID iD
Author: Joel Ruch
Author: Sigurjon Jonsson

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×