HR: 08:45h
AN: C11C-04    [Abstracts]
TI: Glacier Changes in the Cordillera Blanca, Peru, Derived From SPOT5 Imagery, GIS and Field- Based Measurements
AU: * Racoviteanu, A
EM: racovite@colorado.edu
AF: Department of Geography and Institute of Arctic and Alpine Research, 1560 30th St, UCB 450, University of Colorado, Boulder, 80309, United States
AU: * Racoviteanu, A
EM: racovite@colorado.edu
AF: National Snow and Ice Data Center (NSIDC), 1530 30th St., Boulder, CO 80309,
AU: Arnaud, Y
EM: yves.arnaud@ird.fr
AF: IRD, GREAT ICE, LGGE, BP 96, St. Martin D'Hères, 38402, France
AU: Williams, M W
EM: markw@colorado.edu
AF: Department of Geography and Institute of Arctic and Alpine Research, 1560 30th St, UCB 450, University of Colorado, Boulder, 80309, United States
AU: Singh Khalsa, S
EM: sjsk@nsidc.org
AF: National Snow and Ice Data Center (NSIDC), 1530 30th St., Boulder, CO 80309,
AB: There is urgency in deriving an extensive dataset for deriving glacier changes within the Cordillera Blanca, Peru, in a cost-effective and timely manner. Rapid glacial retreat during the last decades in this area poses a threat for water resources, hydroelectric power and local traditions. While there is some information on decadal changes in glacier extents, there still remains a paucity of mass balance measurements and glacier parameters such as hypsometry, size distribution and termini elevations. Here we investigate decadal changes in glacier parameters for Cordillera Blanca of Peru using data from Système Probatoire d'Observation de la Terre (SPOT) sensor, an old glacier inventory from 1970 aerial photography, field-based mass balance measurements and meteorological observations. Here we focus on: constructing a geospatial glacier inventory from 2003 SPOT scenes; mass balance estimations using remote sensing and field data; frequency distribution of glacier area; changes in termini elevations; hypsometry changes over time; glacier topography (slope, aspect, length/width ratio); AAR vs. mass balance for Artesonraju and Yanamarey benchmark glaciers; precipitation and temperature trends in the region. Over the last 25 years, mean temperatures increases of 0.09 deg.C/yr were greater at lower elevation than the 0.01 deg.C/yr at higher elevations, with little change in precipitation. Comparison of the new SPOT-based glacier inventory with the 1970 inventory shows that glaciers in Cordillera Blanca retreated at a rate of 0.6% per year over the last three decades, with no significant differences in the rate of area loss between E and W side. At lower elevations there is an upward shift of glacier termini along with a decrease in glacier area. Small glaciers are losing more area than large glaciers. Based on the relationship between specific mass balance (bn) and accumulation area ratio (AAR) for the two benchmark glaciers, we predicted a steady-state equilibrium line altitude (ELA) of approximately 5050 m for the range as a whole. Additional field work is needed to more accurately establish the bn vs. AAR curves and to better determine the most representative benchmark glacier to use in predicting the response of the entire system to climate changes.
DE: 0720 Glaciers
DE: 0758 Remote sensing
DE: 0762 Mass balance (1218, 1223)
DE: 0772 Distribution
DE: 0798 Modeling
SC: Cryosphere [C]
MN: 2007 Fall Meeting