@misc{10481/85326,
year = {2023},
month = {4},
url = {https://hdl.handle.net/10481/85326},
abstract = {Modern marine settings are experiencing rapid deoxygenation mainly forced by global warming and anthropogenic
eutrophication. Therefore, studies that assess the role of climate variability in large spatiotemporal
deoxygenations during past climate changes are needed to better comprehend the consequences of the current
global warming and ocean deoxygenation. In this respect, deep marine sediments associated to past oxic-toanoxic
transitions are useful palaeoarchives for understanding the interplay between climate variability, deepwater
dynamics and large-scale deoxygenation. Moreover, they can offer long-term perspectives to modern
marine settings that are suffering oxygen depletion due to climate change and anthropogenic pressure. In
particular, sapropel layers from the Middle Pleistocene to the Holocene are excellent palaeoarchives of past
large-scale deoxygenation events, since (i) they occurred during a similar Mediterranean hydrogeographic
configuration to the present, (ii) have a robust chronological control, and (iii) previous studies have reconstructed
the climate conditions that ruled during their deposition. In this work, we have applied empirical
palaeoceanographic conceptual models to five sapropels (S1, S5, S6, S7 and S8) in three Eastern Mediterranean
(EM) settings. The models suggest that the hydrographic regimes of all studied sapropels can be considered as
analogues to those observed in certain modern marine restricted settings. The results obtained support the idea
that climate and the degree of surface-water freshening are the primary factors that influence deep-water dynamics
in marine restricted settings, that in turn control the frequency and intensity of bottom-water deoxygenation
and the stability and depth of the chemocline. The deepest EM sites are the most vulnerable locations to
develop bottom-water restriction and deoxygenation. Local hydrogeographic factors play an essential role in the
extent and frequency of bottom-water deoxygenation. Particulate shuttling was very intense during sapropel
deposition and water-mass exchange between EM and Western Mediterranean controlled the intensity of the
basin reservoir effect and Mo budget in EM.},
organization = {Grants PID2019-104624RB-I00, PID2019-104625RB-100},
organization = {TED2021-131697B-C22 funded by MCIN/AEI/ 10.13039/5011000110
33,},
organization = {Grants FEDER/Junta de Andalucía P18-RT-3804},
organization = {P18-RT-
4074},
organization = {Groups RNM-179},
organization = {RNM-178 funded by Junta
de Andaluca},
organization = {Lausanne University
(Switzerland) for Rock-eval analyses and TOC measurements},
organization = {Center for Scientific Instrumentation (CIC, University
of Granada)},
organization = {XRF Unit of the IACT (CSIC-UGR) for the ICP and
XRF analyses},
publisher = {Elsevier},
keywords = {Mediterranean},
keywords = {Sapropel},
keywords = {Deoxygenation},
keywords = {Climate change},
keywords = {Trace metal},
keywords = {Palaeoceanography},
title = {Role of climate variability on deep-water dynamics and deoxygenation during sapropel deposition: New insights from a palaeoceanographic empirical approach},
doi = {10.1016/j.palaeo.2023.111601},
author = {Monedero Contreras, Ricardo David and Martínez Ruiz, Francisca and Rodríguez Tovar, Francisco J.},
}