Thickness measurements of glaciers from Central-South Chile

The results of ice thickness measurements camied out in Chile (30-41°S) during recent years are presented. The information was obteined by means of radar in five glaciers. In all of them, the radar signals were slightly attenuated allowing penetration of the ice to the bedrock. This means that the presence of supra,

intra and subglacial meltwater did not affect the signals significantly. The system was tested on bare ice as well as debris covered ice. For debris covered ice areas, the signals were much more noisy than on bare ice, but they were able to penetrate the ice to the bedrock, obtaining a maximum thickness of 230

m in the ablation area of Juncal Norte glacier. The analysis of bed and internal reflection power, allowed the characterisation of cold ice for Tapado glacier (without basal sliding) whilst Juncal Norte glacier was recognised as temperate ice. These radar ice thickness measurements have a high accuracy (1 to 6%),

which is much better than other geophysical methods used in Chile, allowing a more accurate and confident estimation of the water equivalent volume storage in the high mountain of this part of the country. An ice thickness measurement programme of representative glaciers from different hydrological basins of the country would improve water resources evaluation, and also allow better monitonng of the glacier variations and responses with respect to the current climate changes affecting that part of the country.