A new global dataset of mountain glacier centerlines and lengths

Abstract

The length of a glacier is a key determinant of its geometry and is an important parameter in glacier inventories and modeling; glacier centerlines are the lines along which the main flow of glaciers takes place and, thus, are crucial inputs for many glaciological applications. In this study, the centerlines and maximum lengths of global glaciers were extracted using a self-designed automatic extraction algorithm based on the latest global glacier inventory data, digital elevation model (DEM), and European allocation theory. The accuracy of the dataset was evaluated through random visual assessments and comparisons with the Randolph Glacier Inventory (RGI) version 6.0. A total of 8.25 % of the outlines of the RGI were excluded, including 10 764 erroneous glacier polygons, 7174 ice caps, and 419 nominal glaciers. A total of 198 137 glacier centerlines were generated, accounting for 99.74 % of the input glaciers. The accuracy of glacier centerlines was 89.68 %. A comparison between the dataset and the previous dataset suggested that most glacier centerlines were slightly longer than those in RGI v6.0, meaning that the maximum lengths of some glaciers had been likely underestimated in the past. The constructed dataset comprises 17 sub-datasets, including global glacier centerlines, maximum lengths, and DEMs, all of which can be found at 10.11922/sciencedb.01643 (Zhang and Zhang, 2022).