A freshwater diatom perspective on the evolution of the southern westerlies for the past-14,000 years in southwestern Patagonia

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dc.contributor.authorVillacis, L. A.
dc.contributor.authorMoreno, P. I.
dc.contributor.authorVilanova, I.
dc.contributor.authorHenriquez, C. A.
dc.contributor.authorHenriquez, W. I.
dc.contributor.authorVilla-Martinez, R. P.
dc.contributor.authorSepulveda-Zuniga, E. A.
dc.contributor.authorMaidana, N. I.
dc.date.accessioned2025-01-20T20:18:26Z
dc.date.available2025-01-20T20:18:26Z
dc.date.issued2023
dc.description.abstractConflicting, even opposite interpretations on the evolution of the Southern Westerly Winds (SWW) are evident in paleoenvironmental records from southwestern Patagonia since the last ice age. These di-vergences call for new approaches utilizing different, ideally independent indicators of paleoenvir-onmental/paleoclimatic change from sensitive sites in climatically relevant locations. Here we present a multidecadally resolved diatom record from Lago Cipreses (51 degrees S), a small closed-basin lake located in a bedrock depression along the eastern foothills of the southern Patagonian Andes. The hydrological balance evolution of this isolated lake affords a direct tie with SWW intensity in a mountainous sector where zonal wind strength and local precipitation are highly correlated. We detect cold-tolerant diatoms (small fragilarioids) between-14-11.9 cal. ka BP followed by a shift to planktonic assemblages (Discostella pseudostelligera, Aulacoseira spp.) under warmer Holocene conditions. Diatom assemblages indicative of stratified water-column conditions (Discostella pseudostelligera, Achnanthidium aff tepidaricola, Achnan-thidium sieminskae) reached their maximum stability between-9.1-7.4 cal. ka BP. Stronger water-column mixing is evident by an abrupt species turnover to Aulacoseira spp. between-7.4-3.1 cal. ka BP, super-imposed on centennial-scale alternations between assemblages since-6.1 cal. ka BP. Cold-tolerant di-atoms resurge at-3.1 cal. ka BP and persist until the present. Our record offers assemblage-based evidence we interpret as sub-centennial to multimillennial scale changes in hydroclimate indicative of: (i) strong SWW influence between-14-11.9 cal. ka BP, (ii) a transition between-11.9-11.3 cal. ka BP to weak SWW influence between-11.3-6.5 cal. ka BP, with a SWW minimum between-9.1-7.4 cal. ka BP, and (iii) strong SWW influence since-6.5 cal. ka BP, with a Holocene SWW maximum since-3.1 cal. ka BP. We posit that enhanced hydroclimate variability since-6.1 cal. ka BP attests to the onset of Southern Annular Mode-like changes at centennial-to sub-centennial timescales. We detect a remarkably coherent and synchronous response of terrestrial and aquatic ecosystems at local scale since-14 cal. ka BP, highlighting the overriding importance of variations in SWW influence in terrestrial and aquatic envi-ronments at multiple timescales.(c) 2022 Elsevier Ltd. All rights reserved.
dc.fuente.origenWOS
dc.identifier.doi10.1016/j.quascirev.2022.107929
dc.identifier.eissn1873-457X
dc.identifier.issn0277-3791
dc.identifier.urihttps://doi.org/10.1016/j.quascirev.2022.107929
dc.identifier.urihttps://repositorio.uc.cl/handle/11534/92462
dc.identifier.wosidWOS:000920327500001
dc.language.isoen
dc.revistaQuaternary science reviews
dc.rightsacceso restringido
dc.subjectSouthwestern Patagonia
dc.subjectSouthern westerly winds
dc.subjectPaleolimnology
dc.subjectHolocene
dc.subjectSouthern annular mode
dc.subjectHydroclimate variability
dc.titleA freshwater diatom perspective on the evolution of the southern westerlies for the past-14,000 years in southwestern Patagonia
dc.typeartículo
dc.volumen301
sipa.indexWOS
sipa.trazabilidadWOS;2025-01-12
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