Extensive hydrothermal activity revealed by multi-tracer survey in the Wallis and Futuna region (SW Pacific)

Autor: Jean-Luc Charlou, Elise Fourré, Yves Fouquet, Ewan Pelleter, Cecile Konn, Jean-Pierre Donval, Philippe Jean-Baptiste, Florian Perez, A.S. Alix, Dominique Birot, Vivien Guyader, Arnaud Gaillot, Arnaud Dapoigny, Joseph A. Resing
Přispěvatelé: Laboratoire Cycles Géochimiques et ressources (LCG), Géosciences Marines (GM), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Allstat, Direction du Végétal et de l'Environnement, Agence Française de Sécurité Sanitaire des Aliments, Institut des Matériaux Jean Rouxel (IMN), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Critical Care Department, Hospital de Sabadell, CIBER Enfermedades Respiratorias, Géochrononologie Traceurs Archéométrie (GEOTRAC), Department of mathematics and computing science [Eindhoven], Eindhoven University of Technology [Eindhoven] (TU/e), Unité de recherche Géosciences Marines (Ifremer) (GM), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN), Institut Français de Recherche pour l'Exploitation de la Mer - Brest (IFREMER Centre de Bretagne)
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Zdroj: Deep Sea Research Part I: Oceanographic Research Papers
Deep Sea Research Part I: Oceanographic Research Papers, 2016, 116 (21), pp.127-144. ⟨10.1016/j.dsr.2016.07.012⟩
Deep-sea Research Part I-oceanographic Research Papers (0967-0637) (Pergamon-elsevier Science Ltd), 2016-10, Vol. 116, P. 127-144
Deep Sea Research Part I: Oceanographic Research Papers, Elsevier, 2016, 116 (21), pp.127-144. ⟨10.1016/j.dsr.2016.07.012⟩
ISSN: 0967-0637
Popis: The study area is close to the Wallis and Futuna Islands in the French EEZ. It exists on the western boundary of the fastest tectonic area in the world at the junction of the Lau and North-Fiji basins. At this place, the unstable back-arc accommodates the plate motion in three ways: (i) the north Fiji transform fault, (ii) numerous unstable spreading ridges, and (iii) large areas of recent volcanic activity. This instability creates bountiful opportunity for hydrothermal discharge to occur. Based on geochemical (CH 4 , TDM, 3 He) and geophysical (nephelometry) tracer surveys: (1) no hydrothermal activity could be found on the Futuna Spreading Centre (FSC) which sets the western limit of hydrothermal activity; (2) four distinct hydrothermal active areas were identified: Kulo Lasi Caldera, Amanaki Volcano, Fatu Kapa and Tasi Tulo areas; (3) extensive and diverse hydrothermal manifestations were observed and especially a 2D distribution of the sources. At Kulo Lasi, our data and especially tracer ratios (CH 4 / 3 He ~50×10 6 and CH 4 /TDM ~4.5) reveal a transient CH 4 input, with elevated levels of CH 4 measured in 2010, that had vanished in 2011, most likely caused by an eruptive magmatic event. By contrast at Amanaki, vertical tracer profiles and tracer ratios point to typical seawater/basalt interactions. Fatu Kapa is characterised by a substantial spatial variability of the hydrothermal water column anomalies, most likely due to widespread focused and diffuse hydrothermal discharge in the area. In the Tasi Tulo zone, the hydrothermal signal is characterised by a total lack of turbidity, although other tracer anomalies are in the same range as in nearby Fatu Kapa. The background data set revealed the presence of a Mn and 3 He chronic plume due to the extensive and cumulative venting over the entire area. To that respect, we believe that the joined domain composed of our active area and the nearby active area discovered in the East by Lupton et al. (2012) highly contribute to the extensive Tonga-Fiji plume and which thus may not originate from a sole source near the Samoa. Our results also emphasize and support the idea that back-arc hydrothermal systems have a significant input to the regional and global ocean and maybe more important than their MOR analogues.
Databáze: OpenAIRE
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