Publication Date:
2022-01-11
Description:
Submarine volcanism represents ~80% of the volcanic activity on Earth and is an important source of mantle-derived gases. These gases are of basic importance for the comprehension of mantle characteristics in areas where subaerial volcanism is missing or strongly modified by the presence of
crustal/atmospheric components. Though, the study of submarine volcanism remains a challenge due to their hazardousness and sea-depth. Here, we report 3He/4He measurements in CO2–dominated gases discharged at 500 m below sea level from the high-temperature (~220 °C) hydrothermal system of the Kolumbo submarine volcano (Greece), located 7 km northeast off Santorini Island in the central part of the Hellenic Volcanic Arc (HVA). We highlight that the mantle below Kolumbo and Santorini
has a 3He/4He signature of at least 7.0 Ra (being Ra the 3He/4He ratio of atmospheric He equal to 1.39×10−6), 3 Ra units higher than actually known for gases-rocks from Santorini. This ratio is also the highest measured across the HVA and is indicative of the direct degassing of a Mid-Ocean-Ridge-
Basalts (MORB)-like mantle through lithospheric faults. We finally highlight that the degassing of high-temperature fluids with a MORB-like 3He/4He ratio corroborates a vigorous outgassing of mantlederived volatiles with potential hazard at the Kolumbo submarine volcano.
Description:
Published
Description:
28013
Description:
1V. Storia e struttura dei sistemi vulcanici
Description:
4V. Vulcani e ambiente
Description:
3A. Ambiente Marino
Description:
JCR Journal
Description:
reserved
Keywords:
Kolumbo
;
submarine volcano
;
3He/4He
;
volcanic gases
;
hydrothermal system
;
volcanic arc
;
Aegean
;
Greece
;
MORB
;
mantle
;
Santorini
;
crustal contamination
;
03. Hydrosphere::03.04. Chemical and biological::03.04.06. Hydrothermal systems
;
04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics
;
04. Solid Earth::04.07. Tectonophysics::04.07.06. Subduction related processes
;
04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics
;
04. Solid Earth::04.07. Tectonophysics::04.07.08. Volcanic arcs
;
04. Solid Earth::04.08. Volcanology::04.08.01. Gases
;
05. General::05.02. Data dissemination::05.02.01. Geochemical data
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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