Late-glacial elevated dust deposition linked to westerly wind shifts in southern South America

VANNESTE, HELEEN; DE VLEESCHOUWER, FRANCOIS; MARTÍNEZ-CORTIZAS, ANTONIO; VON SCHEFFER, CLEMENS; PIOTROWSKA, NATALIA; ANDREA CORONATO; LE ROUX, GAEL

Scientific Reports

Nature Publishing Group

Año: 2015 vol. 5 p. 1 - 10

Atmospheric dust loadings play a crucial role in the global climate system. Southern South America􀂋􀂕􀀃􀂃􀀃􀂍􀂇􀂛􀀃􀂆􀂗􀂕􀂖􀀃􀂕􀂑􀂗􀂔􀂅􀂇􀇡􀀃􀂊􀂑􀂙􀂇􀂘􀂇􀂔􀇡􀀃􀂆􀂗􀂕􀂖􀀃􀂆􀂇􀂒􀂑􀂕􀂋􀂖􀂋􀂑􀂐􀀃􀂔􀂃􀂖􀂇􀂕􀀃􀂔􀂇􀂏􀂃􀂋􀂐􀀃􀂒􀂑􀂑􀂔􀂎􀂛􀀃􀂓􀂗􀂃􀂐􀂖􀂋􀆤􀂇􀂆􀀃􀂕􀂋􀂐􀂅􀂇􀀃􀂖􀂊􀂇􀀃􀂎􀂃􀂕􀂖􀀃􀂉􀂎􀂃􀂅􀂋􀂃􀂎􀀃termination (~17 kyr ago), an important timeframe to anticipate future climate changes. Here weuse isotope and element geochemistry in a peat archive from Tierra del Fuego, to reconstruct􀂃􀂖􀂏􀂑􀂕􀂒􀂊􀂇􀂔􀂋􀂅􀀃􀂆􀂗􀂕􀂖􀀃􀆪􀂗􀂚􀂇􀂕􀀃􀂃􀂐􀂆􀀃􀂃􀂕􀂕􀂑􀂅􀂋􀂃􀂖􀂇􀂆􀀃􀂇􀂐􀂘􀂋􀂔􀂑􀂐􀂏􀂇􀂐􀂖􀂃􀂎􀀃􀂃􀂐􀂆􀀃􀂙􀂇􀂕􀂖􀂇􀂔􀂎􀂛􀀃􀂙􀂋􀂐􀂆􀀃􀂅􀂊􀂃􀂐􀂉􀂇􀂕􀀃􀂈􀂑􀂔􀀃􀂖􀂊􀂇􀀃􀂒􀂃􀂕􀂖􀀃16.2 kyr. Dust depositions were elevated during the Antarctic Cold Reversal (ACR) and second half ofthe Younger Dryas (YD) stadial, originating from the glacial Beagle Channel valley. This increase wasmost probably associated with a strengthening of the westerlies during both periods as dust sourceareas were already available before the onset of the dust peaks and remained present throughout.Congruent with glacier advances across Patagonia, this dust record indicates an overall strengtheningof the wind belt during the ACR. On the other hand, we argue that the YD dust peak is linked to 􀂐􀂉􀀃􀂃􀂐􀂆􀀃􀂒􀂑􀂎􀂇􀂙􀂃􀂔􀂆􀀃􀂕􀂊􀂋􀂈􀂖􀂇􀂆􀀃􀂙􀂇􀂕􀂖􀂇􀂔􀂎􀂋􀂇􀂕􀇤􀀃􀀗􀂊􀂇􀀃􀂅􀂎􀂑􀂕􀂇􀀃􀂋􀂐􀂖􀂇􀂔􀂒􀂎􀂃􀂛􀀃􀂄􀂇􀂖􀂙􀂇􀂇􀂐􀀃􀂆􀂗􀂕􀂖􀀃􀆪􀂗􀂚􀂇􀂕􀀃􀂃􀂐􀂆􀀃􀂅􀂎􀂋􀂏􀂃􀂖􀂋􀂅􀀃􀂅􀂊􀂃􀂐􀂉􀂇􀂕􀀃demonstrates that atmospheric circulation was essential in generating and sustaining present-­‐dayinterglacial conditions.