Investigating collapse structures in oceanic islands using magnetotelluric surveys: The case of Fogo Island in Cape Verde

One of the most remarkable natural events on Earth are the large lateral flank collapses of oceanic volcanoes, involving volumes of rock exceeding tens of km3. These collapses are relatively frequent in recent geological times as supported by evidence found in the geomorphology of volcanic island ed...

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Autores: Martínez Moreno, Francisco José, Monteiro Santos, F. A., Madeira, José, Pous, Jaume, Bernardo, Ivo, Soares, António, Esteves, Miguel, Adão, Filipe, Ribeiro, Joana, Mata, João, Brum da Silveira, António
Tipo de documento: artigo
Data de publicação:2018
País:España
Recursos:Universidad Complutense de Madrid (UCM)
Repositório:Docta Complutense
Idioma:inglês
OAI Identifier:oai:docta.ucm.es:20.500.14352/113097
Acesso em linha:https://hdl.handle.net/20.500.14352/113097
Access Level:Acceso aberto
Palavra-chave:550.838:551.21
Volcanic ocean islands
Magnetotelluric
Flank collapse
Island structure
Resistivity
Geodinámica
Geología
2507 Geofísica
2506 Geología
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oai_identifier_str oai:docta.ucm.es:20.500.14352/113097
network_acronym_str ES
network_name_str España
repository_id_str
spelling Investigating collapse structures in oceanic islands using magnetotelluric surveys: The case of Fogo Island in Cape VerdeMartínez Moreno, Francisco JoséMonteiro Santos, F. A.Madeira, JoséPous, JaumeBernardo, IvoSoares, AntónioEsteves, MiguelAdão, FilipeRibeiro, JoanaMata, JoãoBrum da Silveira, António550.838:551.21Volcanic ocean islandsMagnetotelluricFlank collapseIsland structureResistivityGeodinámicaGeología2507 Geofísica2506 GeologíaOne of the most remarkable natural events on Earth are the large lateral flank collapses of oceanic volcanoes, involving volumes of rock exceeding tens of km3. These collapses are relatively frequent in recent geological times as supported by evidence found in the geomorphology of volcanic island edifices and associated debris flows deposited on the proximal ocean floor. The Island of Fogo in the Cape Verde archipelago is one of the most active and prominent oceanic volcanoes on Earth. The island has an average diameter of 25 km and reaches a maximum elevation of 2829 m above sea level (m a.s.l.) at Pico do Fogo, a young stratovolcano located within a summit depression open eastward due to a large lateral flank collapse. The sudden collapse of the eastern flank of Fogo Island produced a megatsunami ~73 ky ago. The limits of the flank collapse were deduced as well from geomorphologic markers within the island. The headwall of the collapse scar is interpreted as either being located beneath the post-collapse volcanic infill of the summit depression or located further west, corresponding to the Bordeira wall that partially surrounds it. The magnetotelluric (MT) method provides a depth distribution of the ground resistivity obtained by the simultaneous measurement of the natural variations of the electric and magnetic field of the Earth. Two N-S magnetotelluric profiles were acquired across the collapsed area to determine its geometry and boundaries. The acquired MT data allowed the determination of the limits of the collapsed area more accurately as well as its morphology at depth and thickness of the post-collapse infill. According to the newly obtained MT data and the bathymetry of the eastern submarine flank of Fogo, the volume involved in the flank collapse is estimated in ~110 km3. This volume –the first calculated onshore– stands between the previously published more conservative and excessive calculations –offshore– that were exclusively based in geomorphic evidence. The model for the summit depression proposing two caldera collapses preceding the collapse of the eastern flank of Fogo is supported by the MT data.ElsevierUniversidad Complutense de Madrid20182018-01-0120182018-01-01journal articlehttp://purl.org/coar/resource_type/c_6501AMhttp://purl.org/coar/version/c_ab4af688f83e57aainfo:eu-repo/semantics/articleapplication/pdfhttps://hdl.handle.net/20.500.14352/113097reponame:Docta Complutenseinstname:Universidad Complutense de Madrid (UCM)Inglésengopen accesshttp://purl.org/coar/access_right/c_abf2Attribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/info:eu-repo/semantics/openAccessoai:docta.ucm.es:20.500.14352/1130972026-06-02T12:44:21Z
dc.title.none.fl_str_mv Investigating collapse structures in oceanic islands using magnetotelluric surveys: The case of Fogo Island in Cape Verde
title Investigating collapse structures in oceanic islands using magnetotelluric surveys: The case of Fogo Island in Cape Verde
spellingShingle Investigating collapse structures in oceanic islands using magnetotelluric surveys: The case of Fogo Island in Cape Verde
Martínez Moreno, Francisco José
550.838:551.21
Volcanic ocean islands
Magnetotelluric
Flank collapse
Island structure
Resistivity
Geodinámica
Geología
2507 Geofísica
2506 Geología
title_short Investigating collapse structures in oceanic islands using magnetotelluric surveys: The case of Fogo Island in Cape Verde
title_full Investigating collapse structures in oceanic islands using magnetotelluric surveys: The case of Fogo Island in Cape Verde
title_fullStr Investigating collapse structures in oceanic islands using magnetotelluric surveys: The case of Fogo Island in Cape Verde
title_full_unstemmed Investigating collapse structures in oceanic islands using magnetotelluric surveys: The case of Fogo Island in Cape Verde
title_sort Investigating collapse structures in oceanic islands using magnetotelluric surveys: The case of Fogo Island in Cape Verde
dc.creator.none.fl_str_mv Martínez Moreno, Francisco José
Monteiro Santos, F. A.
Madeira, José
Pous, Jaume
Bernardo, Ivo
Soares, António
Esteves, Miguel
Adão, Filipe
Ribeiro, Joana
Mata, João
Brum da Silveira, António
author Martínez Moreno, Francisco José
author_facet Martínez Moreno, Francisco José
Monteiro Santos, F. A.
Madeira, José
Pous, Jaume
Bernardo, Ivo
Soares, António
Esteves, Miguel
Adão, Filipe
Ribeiro, Joana
Mata, João
Brum da Silveira, António
author_role author
author2 Monteiro Santos, F. A.
Madeira, José
Pous, Jaume
Bernardo, Ivo
Soares, António
Esteves, Miguel
Adão, Filipe
Ribeiro, Joana
Mata, João
Brum da Silveira, António
author2_role author
author
author
author
author
author
author
author
author
author
dc.contributor.none.fl_str_mv Universidad Complutense de Madrid
dc.subject.none.fl_str_mv 550.838:551.21
Volcanic ocean islands
Magnetotelluric
Flank collapse
Island structure
Resistivity
Geodinámica
Geología
2507 Geofísica
2506 Geología
topic 550.838:551.21
Volcanic ocean islands
Magnetotelluric
Flank collapse
Island structure
Resistivity
Geodinámica
Geología
2507 Geofísica
2506 Geología
description One of the most remarkable natural events on Earth are the large lateral flank collapses of oceanic volcanoes, involving volumes of rock exceeding tens of km3. These collapses are relatively frequent in recent geological times as supported by evidence found in the geomorphology of volcanic island edifices and associated debris flows deposited on the proximal ocean floor. The Island of Fogo in the Cape Verde archipelago is one of the most active and prominent oceanic volcanoes on Earth. The island has an average diameter of 25 km and reaches a maximum elevation of 2829 m above sea level (m a.s.l.) at Pico do Fogo, a young stratovolcano located within a summit depression open eastward due to a large lateral flank collapse. The sudden collapse of the eastern flank of Fogo Island produced a megatsunami ~73 ky ago. The limits of the flank collapse were deduced as well from geomorphologic markers within the island. The headwall of the collapse scar is interpreted as either being located beneath the post-collapse volcanic infill of the summit depression or located further west, corresponding to the Bordeira wall that partially surrounds it. The magnetotelluric (MT) method provides a depth distribution of the ground resistivity obtained by the simultaneous measurement of the natural variations of the electric and magnetic field of the Earth. Two N-S magnetotelluric profiles were acquired across the collapsed area to determine its geometry and boundaries. The acquired MT data allowed the determination of the limits of the collapsed area more accurately as well as its morphology at depth and thickness of the post-collapse infill. According to the newly obtained MT data and the bathymetry of the eastern submarine flank of Fogo, the volume involved in the flank collapse is estimated in ~110 km3. This volume –the first calculated onshore– stands between the previously published more conservative and excessive calculations –offshore– that were exclusively based in geomorphic evidence. The model for the summit depression proposing two caldera collapses preceding the collapse of the eastern flank of Fogo is supported by the MT data.
publishDate 2018
dc.date.none.fl_str_mv 2018
2018-01-01
2018
2018-01-01
dc.type.none.fl_str_mv journal article
http://purl.org/coar/resource_type/c_6501
AM
http://purl.org/coar/version/c_ab4af688f83e57aa
dc.type.openaire.fl_str_mv info:eu-repo/semantics/article
format article
dc.identifier.none.fl_str_mv https://hdl.handle.net/20.500.14352/113097
url https://hdl.handle.net/20.500.14352/113097
dc.language.none.fl_str_mv Inglés
eng
language_invalid_str_mv Inglés
language eng
dc.rights.none.fl_str_mv open access
http://purl.org/coar/access_right/c_abf2
Attribution-NonCommercial-NoDerivatives 4.0 International
http://creativecommons.org/licenses/by-nc-nd/4.0/
dc.rights.openaire.fl_str_mv info:eu-repo/semantics/openAccess
rights_invalid_str_mv open access
http://purl.org/coar/access_right/c_abf2
Attribution-NonCommercial-NoDerivatives 4.0 International
http://creativecommons.org/licenses/by-nc-nd/4.0/
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Elsevier
publisher.none.fl_str_mv Elsevier
dc.source.none.fl_str_mv reponame:Docta Complutense
instname:Universidad Complutense de Madrid (UCM)
instname_str Universidad Complutense de Madrid (UCM)
reponame_str Docta Complutense
collection Docta Complutense
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15,812429

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