Glaciares de Chile


"Elevation change and ice flow at Horseshoe Valley, Patriot Hills, Antarctica"

Casassa, G., A. Rivera, C. Acuña, H. Brecher and H. Lange (2004) : “Elevation change and ice flow at Horseshoe Valley, Patriot Hills, Antarctica” Annals of Glaciology, 39, 20 – 28.

Resumen / Abstract.

Patriot Hills is located at 80º18′ S, 81º22’W, at the southernmost end of the Heritage Range, Ellsworth Mountains, West Antarctica. A comparison of glacier elevation data and ice velocities obtained by the differential global positioning system in the period 1996–97 is presented. Ablation/ accumulation rates measured at a network of stakes in Horseshoe Valley show average accumulation of 70 kgm-2 a-1 in the central part of the valley, and a maximum ablation of 170 kgm-2 a-1 at the edge of the blue-ice area, close to Patriot Hills. Changes in the surface elevation of the glacier measured at 81 stakes in the period 1995–97 show a mean thickening of þ0.43 0.42ma-1, which, considering the uncertainties, indicates that the ice sheet around Patriot Hills is in near steady state. Surface velocities, in combination with ice thicknesses obtained by ground-based radio-echo sounding, are used to compute the ice flux across the Horseshoe Valley transect. A total outflow of 0.44 – 0.08km3 a-1 is obtained. Considering a catchment area for Horseshoe Valley of 1087km2 upstream from the flow transect, and a net accumulation rate of 100 kgm-2 a-1, a total input of 0.11 – 0.04km3 a-1 by snow accumulation is obtained.