Glacier thickness and ice volume of the Northern Andes

Abstract

Tropical glacier melt provides valuable water to surrounding communities, but climate change is projected to cause the demise of many of these glaciers within the coming century. Understanding the future of tropical glaciers requires a detailed record of their thicknesses and volumes, which is currently lacking in the Northern Andes. We calculate present-day (2015–2021) ice-thicknesses for all glaciers in Colombia and Ecuador using six different methods, and combine these into multi-model ensemble mean ice thickness and volume maps. We compare our results against available field-based measurements, and show that current ice volumes in Ecuador and Colombia are 2.49 ± 0.25 km3 and 1.68 ± 0.24 km3 respectively. We detected no motion on any remaining ice in Venezuela. The overall ice volume in the region, 4.17 ± 0.35 km3, is half of the previous best estimate of 8.11 km3. These data can be used to better evaluate the status and distribution of water resources, as input for models of future glacier change, and to assess regional geohazards associated with ice-clad volcanoes.