scholarly journals Laboratory studies of high Rayleigh number circulation in an open-top Hele-Shaw cell: An analog to mid-ocean ridge hydrothermal systems

2001 ◽  
Vol 106 (B6) ◽  
pp. 10983-11000 ◽  
Author(s):  
Abdellah S. M. Cherkaoui ◽  
William S. D. Wilcock
Keyword(s):  
Rayleigh Number ◽  
Hydrothermal Systems ◽  
Laboratory Studies ◽  
Mid Ocean Ridge ◽  
Ocean Ridge ◽  
Hele Shaw Cell

scholarly journals A Si-Cl geothermobarometer for the reaction zone of high-temperature, basaltic-hosted mid-ocean ridge hydrothermal systems

2009 ◽  
Vol 10 (5) ◽  
pp. n/a-n/a ◽  
Author(s):  
Fabrice J. Fontaine ◽  
William S. D. Wilcock ◽  
Dionysis E. Foustoukos ◽  
David A. Butterfield
Keyword(s):  
High Temperature ◽  
Reaction Zone ◽  
Hydrothermal Systems ◽  
Mid Ocean Ridge ◽  
Ocean Ridge

Fluids in Submarine Mid-Ocean Ridge Hydrothermal Settings

Elements ◽  
2020 ◽  
Vol 16 (6) ◽  
pp. 389-394
Author(s):  
Esther M. Schwarzenbach ◽  
Matthew Steele-MacInnis
Keyword(s):  
Heat Budget ◽  
Oceanic Lithosphere ◽  
Life Forms ◽  
Hydrothermal Systems ◽  
Hydrothermal Fluids ◽  
Early Earth ◽  
Geologic Time ◽  
Mid Ocean Ridge ◽  
Time Changes ◽  
Ocean Ridge

Seawater interaction with the oceanic lithosphere crucially impacts on global geochemical cycles, controls ocean chemistry over geologic time, changes the petrophysical properties of the oceanic lithosphere, and regulates the global heat budget. Extensive seawater circulation is expressed near oceanic ridges by the venting of hydrothermal fluids through chimney structures. These vent fluids vary greatly in chemistry, from the metal-rich, acidic fluids that emanate from “black smokers” at temperatures up to 400 °C to the metal-poor, highly alkaline and reducing fluids that issue from the carbonate–brucite chimneys of ultramafic-hosted systems at temperatures below 110 °C. Mid-ocean ridge hydrothermal systems not only generate signifi-cant metal resources but also host unique life forms that may be similar to those of early Earth.

Seawater dissolved gases associated with hydrothermal fluids in convergent margins (Brandsfield-South Shetland, Antarctica) and mid-ocean ridge and intraplate settings (Azores, Portugal)

2020 ◽  
Author(s):  
María Asensio-Ramos ◽  
Cecilia Amonte ◽  
Esther Santofimia ◽  
Gladys V. Melián ◽  
Enrique López ◽  
...  
Keyword(s):  
Water Column ◽  
Sea Water ◽  
Volcanic Eruptions ◽  
Isotopic Signature ◽  
Hydrothermal Systems ◽  
Hydrothermal Fluids ◽  
Convergent Margins ◽  
Dissolved Gases ◽  
Mid Ocean Ridge ◽  
Ocean Ridge

<p>The occurrence of hydrothermal emissions implies the existence of heat sources related to magma reservoirs both in convergent margins (Bransfield-South Shetland) and in mid-ocean ridge and intra-plate settings (Azores). The importance of these systems lies in (a) producing important mineralizations,  (b) favouring extremophilic ecosystems, (c) being precursors of underwater volcanic eruptions, (d) playing a major role they play in the matter and energy exchange between the geosphere and the hydrosphere and (d) their impact on the geochemistry of the oceans. In subduction margins, rifts, transforming faults or volcanic buildings in hot spots, emissions of hot fluids related to magmas and/or circulation in hydrothermal systems can occur. The fluids associated with magmas are fundamentally gases (CO<sub>2</sub>, H<sub>2</sub>O, H<sub>2</sub>, SO<sub>2</sub>, H<sub>2</sub>S, He, etc.). Hydrothermal fluids constitute a complex system where seawater percolates through fissures and fractures in sediments and rocks at different depths and heats up upon contact with magmas and hot volcanic rocks, leaching a large amount of chemical elements. The identification of acoustic plumes in the water column is the first step in the exploration of unknown underwater emissions. The new acoustic detection technologies, which operate with a wide frequency range, are one of the most innovative tools for detecting gas plumes and other fluids in the water column, especially in deep waters. Once detected, physical-chemical parameters (temperature, salinity, turbidity, cations, anions, dissolved gases, isotopic signature, etc.) that allow their characterization and classification will be determined. This type of studies is particularly useful when it is not possible to collect free gases, fumarolic and/or bubbling gases, as in the case of submarine activity. In this work, we show the results obtained regarding the chemical composition of dissolved gases (He, H<sub>2</sub>, CO<sub>2</sub> (aq), O<sub>2</sub>, N<sub>2</sub>, CH<sub>4</sub> and He) and isotopic signature of the dissolved CO<sub>2</sub> (δ<sup>13</sup>C-CO<sub>2</sub>) in sea water sampled in sites of hydrothermal interest. With this purpose, we carried out two oceanographic surveys (EXPLOSEA1 and EXPLOSEA2) in 2019: the first in Antarctica aboard the Spanish Research Vessel (RV) Hespérides and the second in North Atlantic Ocean aboard the Spanish RV Sarmiento de Gamboa. To do so, 13 and 10 water vertical profiles were studied in the RV Hespérides and the RV Sarmiento de Gamboa, respectively, using a SBE 911plus CTD system where there was evidence of acoustic plumes or where appropriate, emission buildings of fluids were present. Water samples were kept in glass bottles for subsequent analysis. The establishment of the physicochemical characteristics of volcanic hydrothermal fluids and the characterization of the nature and origin of the different types of fluid emissions will help to classify the hydrothermal fluids in order to understand the phenomena that take place in them and their surroundings.</p>

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