Improving glacier volume-area scaling to better quantify tropical Andean glacial water resources from remote sensing

Tropical glaciers are an important component of the water budget for high-altitude catchments in much of the central Andes. The majority of tropical Andean glaciers are small, but it has been suggested that because of their numbers the volume of water they contain is significant. Unfortunately, the ice volume measurements needed to inform decision makers have been made for only a handful of tropical glaciers. In August 2012, with the assistance of the Instituto Geográfico Militar in Bolivia, ground penetrating radar (GPR) and differential Global Positioning System (dGPS) measurements were collected along transects totaling 3,189 m in length on the Charquini SE cirque glacier. This small cirque glacier which is located in the southern portion of the Cordillera Real in Bolivia had an approximate surface area in 2012 of 02.42 square kilometers. Our initial observations indicate that the GPR survey was able to adequately capture the ice bedrock interface. Ordinary Kriging was used to develop maps of surface and subsurface topography from the dGPS and GPR observations. In 2012, the Charquini SE glacier contained a minimum of 3,900,000 cubic meters of ice. This information, along with other recent volume measurements for tropical and sub-tropical Andean glaciers, was used to update earlier volume-area scaling relationships established for these glaciers. This relationship will then be applied to determine the volume of water currently stored in tropical Andean glaciers based on previous research on glaciers areas using remote sensing.