The first data on carbon and nitrogen in the mantle of North Antarctica emerge from the Deception Island volcano: analyses by the INGV show that even surface ecosystems contribute to shaping the deep interior of the planet.
Chemical differences in the Earth's mantle immense they depend only from the characteristics inherited from the beginning of the history of our planet (the primordial component) from the deep processes, but also from what happens on the surface and is transferred to the interior of our planet in the subduction zones, that is, the areas where one tectonic plate slides under another.
This is what emerges from the results of the study Volatiles in the mantle below Northern Antarctica: Insights from Deception Island volcano, which directly involves theIstituto Nazionale di Geofisica e Vulcanologia (INGV) on Deception Island volcano, North Antarctica, published in the magazine Gondwana ResearchThe research arises from the project Erupting by Prof. Antonio Alvarez Valero of the University of Salamanca (Spain), who has decades of experience in studying this volcano.
The work analyzes the gases emitted by the active volcanic system and provides the first data characterizing carbon and nitrogen in the Earth's mantle in this previously little-studied sector of the planet.
The results indicate that helium and carbon reflect a composition similar to that of the mantle called MORB, typical of mid-ocean ridges, while nitrogen shows unexpected enrichment compared to the typical values of the same mantle source.
According to the researchers, this anomaly è linked to the transport of surface materials to depth during subductionIn particular, materials from high-latitude marine ecosystems, characterized by a low carbon-to-nitrogen ratio, are entrained in the mantle and modify its composition with a different imprint than in other geographical areas.
"For the first time we have data characterizing carbon, nitrogen and noble gases in the mantle in this sector of the planet, Antarctica. These Results clearly show that the Earth's surface can leave a deep imprint on the mantle", points out Antonio Caracausi, researcher at INGV and author of the study.
“The results of the study suggest that there is a link between surface ecosystems and deep processes of the planet, an aspect that has been little explored until now.”, adds the researcher.
Research shows that the recycling of gases and volatile elements towards the interior of the Earth is controlled not only by the presence of subduction zones, ma also from their location geographic.
This This process contributes to making the mantle chemically heterogeneous and opens new perspectives for understanding the deep evolution of our planet..
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Photo 1 - Scientific research amid the stillness and monochromatic symmetry of Antarctica. Photo credit: INGV.
Photo 2 - The study stems from a Spanish project (University of Salamanca), and used the Spanish Antarctic base "Gabriel de Castilla." During non-Spanish personnel's stay at the base, the flags of the various nations are raised to signal the presence of other countries. Photo credit: INGV.
Photo 3 - CFumaroles on the beach. Photo credit: INGV.