Trans-pacific glacial response to the antarctic cold reversal in the southern mid-latitudes
Artículo

Fecha
2018-05-15Metadatos
Mostrar el registro completo del ítem
Cómo citar
Sagredo, Esteban A.
Cómo citar
Trans-pacific glacial response to the antarctic cold reversal in the southern mid-latitudes
Compartir:
cargando...
Copiar
Autor
Resumen
Elucidating the timing and regional extent of abrupt climate events during the last glacial-interglacial transition (similar to 18-11.5 ka) is critical for identifying spatial patterns and mechanisms responsible for large-magnitude climate events. The record of climate change in the Southern Hemisphere during this time period, however, remains scarce and unevenly distributed. We present new geomorphic, chronological, and equilibrium line altitude (ELA) data from a climatically sensitive mountain glacier at Monte San Lorenzo (47 degrees S), Central Patagonia. Twenty-four new cosmogenic Be-10 exposure ages from moraines provide a comprehensive glacial record in the mid-latitudes of South America, which constrain the timing, spatial extent and magnitude of glacial fluctuations during the Antarctic Cold Reversal (ACR, similar to 14.5-12.9 ka). Rio Tranquilo glacier advanced and reached a maximum extent at 13.9 +/- 0.7 ka. Three additional inboard moraines afford statistically similar ages, indicating repeated glacier expansions or marginal fluctuations over the ACR. Our record represents the northernmost robust evidence of glacial fluctuations during the ACR in southern South America, documenting not only the timing of the ACR maximum, but also the sequence of glacier changes within this climate event. Based on ELA reconstructions, we estimate a cooling of >1.6-1.8 degrees C at the peak of the ACR. The Rio Tranquilo record along with existing glacial reconstructions from New Zealand (43 degrees S) and paleovegetation records from northwestern (41 degrees S) and central-west (45 degrees S) Patagonia, suggest an uniform trans-Pacific glacier-climate response to an ACR trigger across the southern mid-latitudes. We posit that the equatorial migration of the southern westerly winds provides an adequate mechanism to propagate a common ACR signal across the Southern Hemisphere. (C) 2018 Elsevier Ltd. All rights reserved.
Indización
Artículo de publicación ISI
Identificador
URI: http://repositorio.uchile.cl/handle/2250/151874DOI: 10.1016/j.quascirev.2018.01.011
Cita del ítem
Quaternary Science Reviews 188 (2018) 160-166Colecciones
Los siguientes archivos de licencia se asocian a este ítem: