CICTERRA   20351
CENTRO DE INVESTIGACIONES EN CIENCIAS DE LA TIERRA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Climate-induced rhythmic oscillations in a stable glacier: Patagonia's Perito Moreno Glacier
Autor/es:
DEPETRIS, P.J., PASQUINI, A.I.
Lugar:
Puerto Madryn
Reunión:
Congreso; XIV REUNION ARGENTINA DE SEDIMENTOLOGÍA; 2014
Institución organizadora:
Asociación Argentina de Sedimentología
Resumen:
. In a
long-term framework, most world glaciers are currently retreating, although a few appear
stable or, sometimes, even advancing. Perito Moreno is a fast-flowing water-calving
glacier in the Patagonian Andes, known for its stability and the concurrent rhythmic
dynamics that causes the periodic ice-damming of Brazo Rico(a branch of Lake
Argentino),and the ensuing collapse of the glacial terminus at the Magallanes
peninsula. The system drains to the Atlantic Ocean through the Santa Cruz
River. Main climatic variables appear to be coherent with ENSO; trend analysis
of the 57 years-long Santa Cruz River flow series shows a significant discharge
increase attributable to (austral) wintertime precipitation and springtime melt
water. Here we show that the glacier?s high-frequency ice-blocking is driven by
the interaction of El Niño-Southern Oscillation (ENSO) and the Antarctic
Oscillation (AAO)both of which may be coupled or decoupled, with the AAO reinforcing
or lessening the effect of ENSO over the southern Pacific region. The sporadic occurrence
of La Niña (reinforced by a weak or positive AAO) or the absence of an El Niño
event may delay or preclude damming events. Although a similar system may be
active elsewhere, Moreno?s rhythm appears as a remarkable high-frequency controlling
mechanism determined by specific climatic variables.