EU project SponGES
Published November 4, 2020 | Version v1
Journal article Open

Multidisciplinary Scientific Cruise to the Northern Mid-Atlantic Ridge and Azores Archipelago

Creators

  • 1. Marine Geology Dv., Geological Survey of Spain IGME, Madrid, Spain
  • 2. ortuguese Task Group for the Extension of the Continental Shelf EMEPC, Paço de Arcos, Portugal
  • 3. Instituto Volcanológico de Canarias INVOLCAN, Santa Cruz de Tenerife, Spain
  • 4. IMAR Instituto do Mar, Universidade dos Açores, Horta, Portugal; Okeanos Research Center, Universidade dos Açores, Horta, Portugal
  • 5. Hydrographic Institute of the Navy IHM, Cádiz, Spain
  • 6. Department of Mineralogy and Petrology, Complutense University of Madrid UCM, Madrid, Spain
  • 7. ortuguese Task Group for the Extension of the Continental Shelf EMEPC, Paço de Arcos, Portugal; GeoBioTec, Aveiro University, Aveiro, Portugal
  • 8. Department of Geobiology, Georg-August University Göttingen, Göttingen, Germany
  • 9. IMAR Instituto do Mar, Universidade dos Açores, Horta, Portugal; Okeanos Research Center, Universidade dos Açores, Horta, Portugal; MARE – Marine and Environmental Sciences Center, Coimbra, Portugal
  • 10. ortuguese Task Group for the Extension of the Continental Shelf EMEPC, Paço de Arcos, Portugal; Institute of Earth Sciences, Department of Geosciences, Évora University, Evora, Portugal

Description

ABSTRACT

This work presents the preliminary result of the multidisciplinary cruise EXPLOSEA2 surveying the northern Mid-Atlantic Ridge and Azores Archipelago from 46◦ 30′ N to 38◦ 30′ N aboard the R/V Sarmiento de Gamboa and ROV Luso over 54 days (June 11 to July 27, 2019). In this cruise report, we detail the geophysical, hydrographic, geological, oceanographic, ecological, and microbiological data acquired and a brief of main findings. The cruise addressed the exploration and comprehensive characterization of venting sites, including the water column, the sediments and rocks that host the hydrothermal activity, and the associated mineralizations, biology, and microbiology. Deep hydrothermal chimneys and massive sulfide deposits (up 3,000 m in depth) within the Moytirra hydrothermal active field were identified on slopes that had not been explored previously. Another striking finding made during the EXPLOSEA2 cruise was the field of carbonate chimneys named the “Magallanes-Elcano” field, a potentially relict ultramafic-hosted hydrothermal site sourced by abiotic methane. This field is related to a serpentinite and gabbro rock outcropping on a dome-shaped massif named the “Iberian Massif.” An outstanding finding of the EXPLOSEA2 survey was the identification of the first garden of soft corals growing after active submarine eruptions were reported in the Azores Archipelago composed by a high density of soft corals the suborder Alcyoniina at the summit and flanks of a recent volcanic cone at 160 m water depth developed during the 1957–1958 eruption of Capelinhos. Several cold-water coral habitats formed by colonial scleractinians (e.g., Lophelia pertusa and Madrepora oculata), coral gardens composed of mixed assemblages of black corals (Leiopathes sp.), and octocorals and dense aggregations of the glass sponge Pheronema carpenteri that may be classified as vulnerable marine ecosystems (VMEs) have been discovered during the EXPLOSEA2 cruise along the northern Mid-Atlantic Ridge. This work reveals the importance of multidisciplinary surveys to the knowledge of deep-sea environments.

Notes

ACKNOWLEDGEMENTS We are grateful to the captain, officers, and the crew of the R/V Sarmiento de Gamboa for their dedication during the EXPLOSEA2 cruise. Special thanks to the technicians of the UTM (CSIC), including acoustic, seismic mechanics, and computers, for their dedication and professionalism during the cruise. We also thank Manuel C. Fernandes, marine mammal observer (MMO), for his seismic works dedication and recommendations, which were strictly followed during the cruise. The EXPLOSEA2 cruise benefits from the Scientific Agreement between Spain and Portugal to share oceanographic vessels and ROV. Thanks to the Azorean Regional Government (GRA) for their facilities and support to investigate marine protected areas. DATA AVAILABILITY STATEMENT The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation. GIS data (multibeam and multichannel seismic tracks, CTDs and ROV stations) can be downloaded from the EXPLOSEA website at: http://www.igme.es/explosea/dataset.html. AUTHOR CONTRIBUTIONS LS: chief scientist of the cruise, writing, and overall organization. TM: co-chief (Geophysics) and writing. FG, CD, LR, and PM: petrology description and writing. AC, AA, RB, BR, and MS: ROV pilots and writing. MA-R: gas geochemistry and writing. MA, MC-S, and IT: biological sampling and writing. IB: GIS system and dataset. JC, CC, and SM: multibeam processing and imaging. EL-P and ES: water geochemistry and writing. BR-T: microbiology and writing. CV: hydrography and writing. All authors contributed to the article and approved the submitted version. FUNDING The EXPLOSEA2 cruise was funded by the Spanish Ministry for Science and Innovation as part of the project EXPLOSEA (grant CTM201675947-R). This study also benefits from the Atlantic Seabed Mapping International Working Group (ASMIWG) as part of the Atlantic Ocean Research Alliance Coordination and Support Action (AORA-CSA). This study is a contribution to the EMODNET-Geology project (EASME/EMFF/2018/1.3.1.8-Lot 1/SI2.811048) and the European project H2020 GeoERA-MINDeSEA (Grant Agreement No. 731166, project GeoE.171.001). MC-S was supported by the European Union's Horizon 2020 research and innovation program under grant agreement no. 678760 (ATLAS). CV is supported by the Fundação para a Ciência e a Tecnologia (FCT) under the Ph.D. fellowship (SFRH/BD/129683/2017), FunAzores -ACORES 01-0145-FEDER-000123 grant, FCT strategic project UID/05634/2020 and SponGES project, European Union's Horizon 2020 research and innovation programme under grant agreement No. 679849.

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Is derived from
Journal article: https://www.frontiersin.org/articles/10.3389/fmars.2020.568035/full#h7 (URL)
Is supplemented by
Figure: https://www.frontiersin.org/articles/10.3389/fmars.2020.568035/full#supplementary-material (URL)

Funding

SponGES – Deep-sea Sponge Grounds Ecosystems of the North Atlantic: an integrated approach towards their preservation and sustainable exploitation 679849
European Commission
ATLAS – A Trans-AtLantic Assessment and deep-water ecosystem-based Spatial management plan for Europe 678760
European Commission
GeoERA – Establishing the European Geological Surveys Research Area to deliver a Geological Service for Europe 731166
European Commission