INSTITUTO ARGENTINO DE NIVOLOGIA, GLACIOLOGIA Y CIENCIAS AMBIENTALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Geometric evolution of the Horcones Inferior Glacier (Mt. Aconcagua, Central Andes) during the 2002-2007 surge
PITTE, P.; BERTHIER, E.; MASIOKAS, M.H.; CABOT, V.; RUIZ, LUCAS; FERRRI HIDALGO, L.
Los Reyunos, Mendoza
Workshop; IAI CRN 2047. Documenting Understanding and projecting changes in the hydrological cycle in the American Cordillera; 2014
Surging glaciers have a particular dynamic behavior, oscillating between two flow modes. During the quiescent phase, which lasts years to decades, the flow is slow and ice accumulates in the reservoir area. During the active phase, which lasts months to years, the flow accelerates to speeds ca. 10-100 times normal and ice is transferred to the receiving area. There are few detailed studies of glacier surges in the Central Andes. In this work we analyzed velocity and elevation changes during a recent surge of Horcones Inferior Glacier that took place between 2002 and 2007. We used 24 ASTER and 8 LANDSAT satellite images to produce velocity fields through accurate sub-pixel orthorectification and cross correlation of the images. We also used the SRTM and 33 ASTER DEM to measure ice elevation changes. The buildup phase lasted until May 2002 during which little motion (0.2±0.1 m/day) was observed. During the surge phase (July 2002-February 2007) a wave propagated through the entire glacier. Velocities rose rapidly to a maximum of 13.5±0.5 m/day during December 2003-January 2004. In February 2005 the surge overrode the previous frontal position leading to a 2.3 km glacier advance that terminated in February 2007. The depletion phase started in 2007. Since then only localized motion has been observed on the glacier and a general lowering of the surface of 4-16 m has taken place until 2014. The surge front was 25-45 m high and the ice volume transferred from the reservoir to the receiving part was approximately 100 hm3.