Seed Grant: Quantifying tropical Andean ice volume loss


Tropical Andean glacier recession is an example of a global climate change phenomenon with profound local consequences for water resources. Widespread reduction in tropical glacier extent is one of the clearest examples of recent climate changes consistent with the notion that high elevation mountains extending to the mid-troposphere will experience greater warming (Bradley et al., 2006). As such, this issue has direct bearing on questions of water supply and abrupt climate changes, as addressed by the CWC core project, Low-latitude glacier retreat. To evaluate the hydrological storage and climatic implications of glacier recession, the actual mass of ice involved is a critical but problematic variable (Mark and Seltzer, 2005). Relatively few glaciers, especially in the remote tropical highlands, feature mass balance monitoring and systematic mapping efforts are rare. Yet satellite and airborne altimetry provide the opportunity to investigate the volume and spatial nature of Andean glacier recession with high resolution digital elevation data.

This project established a cross-college collaborative team with relevant expertise to investigate recent volumetric changes in the Quelccaya Ice Cap (QIC) in the country of Peru. The seed grant was strategically designed to: (1) complement the core project; (2) leverage an existing NASA grant (New Investigator Program Grant #NNX06AF11G to BGM); and (3) expand the capacity for future collaborative scientific efforts in a region with a strong heritage of OSU excellence. The central objective was to collaboratively investigate the availability of satellite radar altimetry (RA) data over the QIC to complement existing and planned surface elevation data. Many satellite altimetry (RA and laser altimetry, or ICESat) data sources exist that can potentially provide additional surfaces to refine estimates of changes in mass loss rate over more recent times. RA (via retracking) of the relatively flat ice QIC surface is theoretically feasible, especially for the longer (decadal or longer) records of radar altimetry (e.g., TOPEX; and also ENVISAT). However, considerable effort is required to assimilate these data sources. To facilitate a new cross-college partnership between B.G. Mark and C.K. Shum, seed grant funds were requested to support a single graduate student.

Project Status

The project has successfully established new interdisciplinary research collaboration and accomplished the central objectives of querying and compiling available RA data for the QIC. Computers have been set up in lab space allocated to the Glacier Environmental Change group at the Byrd Polar Research Center. Satellite data and aerial photos have been collected from 1962 to 2008 in order to calculate surface elevation data and depth changes for the ice cap.


Bryan Mark
Department of Geography
College of Social and Behavioral Sciences