Tore Pool: a singular sediment trap for paleoproductivity in the North Atlantic gyre

• Main Authors: Martín Lebreiro, Susana, Antón López, Laura Ángela, Nave, Sílvia, Kissel, Catherine
• Format: Conference Object
• Language: English
• Published: 2022
• Subjects: Tore seamount; natural sediment-trap; ocean productivity; deep-sea circulation; subtropical gyre; Antarctic; Antarc*; North Atlantic
• Online Access: http://hdl.handle.net/10261/273636

International Conference on Paleoceanography (12º. 2016. Utrecht) The Tore pool is a 5.5 km conical deep basin within the Tore seamount, located 300 km off the Iberian margin in the North Atlantic at 40°N of latitude. The vacant Tore seamount acts as a natural, giant sediment trap, and anticipates a singular environment where many biogeochemical and physical processes converge into an isolated and confined space from the open deep ocean. Trapped vertical particle flux of surface productivity is deposited without sediment resuspension and erosion by bottom currents. The Tore pool has a restricted gate for exchange of Atlantic deep waters. This implies a potential better preservation of inside deep sea carbonates compared to the North Atlantic open ocean, protected from O-rich Antarctic Bottom Water (AABW) over glacial stages. Additionally, limited O into the pool would favour seldom anoxic conditions by consumption of organic matter. We base our study on the 25 m long Calypso Giant core MD13-3473 taken within the Tore pool, where geochemical and physical analyses are being performed. The sequence covers the last 400 thousand years (down to Marine Isotope Stage 11). Orbital as well as millennial scale climate changes are present in the records. In this case, an accurate stratigraphy is crucial, as it is the identification of occasional gravitational facies, and critical for the purpose of estimation of sedimentation rate and vertical fluxes. Estimation of marine biomass and productivity fluxes in areas of subtropical gyres, contributes to understand capacity of global marine sequestration of atmospheric gases at orbital scale. Instituto Geológico y Minero de España, España Laboratorio Nacional de Energia e Geología, Portugal Laboratoire des Sciences du Climat et de l'Environnement, Centre National de la Recherche Scientifique, France Laboratoire des Sciences du Climat et de l'Environnement, Université Paris-Saclay, France