First surface velocity maps for glaciers of Monte Tronador, North Patagonian Andes, derived from sequential Pleiades satellite images

RUIZ, LUCAS; BERTHIER, E.; MASIOKAS, MARIANO; PITTE, P.; VILLALBA, RICARDO

JOURNAL OF GLACIOLOGY

INT GLACIOL SOC

Lugar: London; Año: 2015

0022-1430

In this paper, we use cross correlated images from the French Pleiades satellite to generate accurate, high resolution seasonal surface velocity maps of Monte Tronador glaciers (ca. 41°S). Local changes in the surface velocity magnitudes, flow patterns and the spatial and sub seasonal changes in surface speed were developed for four consecutive periods at the transition between the ablation and the accumulation seasons in March-June 2012. The resulting maps reproducewith great detail different surface velocity features including increasing surface speeds where ice flux is constrained or no movement in areas of stagnant ice. We also found that glaciers located at higher elevations (i.e above 1500 m asl) show a decrease in surface velocity at the beginning of the accumulation season. In contrast, debris-cover glacier tongues reaching the lower elevations (i.e. below 1000 m asl) showed the maximum surface velocities during this period. This opposite behavior is interpreted in term of contrasting input of meltwater and rain to the subglacial system. Among other applications, these surface velocity maps could help to identify the controls on surface velocity, aid in the delimitation of ice divides between Monte Tronador glaciers, andcontribute to a more realistic calibration of ice flux-mass balance models.