![Sample our Earth Sciences journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5930/TOC-Subject-Sample-2021-Earth-Sciences.jpg"})
Abstract
Ten cirque glaciers and their Neoglacial deposits were studied in the Pangnirtung Fiord area of Baffin Island to determine the origin of glacial debris and the erosion rates of subpolar glaciers. Aerial photographs, topographic maps, laboratory work, and field surveys provided information on glacier and cirque areas, volume, texture and source of till.
The rate of debris production for glaciers of this study was 24 to 155 m3 yr–1. Clast rounding indicates that 84 to 96% of the till may be subglacially derived, and was produced at a rate of 22 to 140 m3 yr–1. Rockfall rates were low in the Baffin Island cirques, averaging 1 to 22 m3 yr–1. Grain-size analyses of Baffin Island Neoglacial tills indicate that they contain little silt (5%) and clay (1%). Abrasion is probably negligible at the base of the Baffin glaciers. The low amounts of silt and clay suggest the glaciers are either wholly or partly frozen to their beds.
Computed rates of total erosion by the glaciers of this study range from 8 to 76 mm. · 1000 yr–1, and are one to two times lower than those for Arapaho Glacier in Colorado. Glaciers occupying cirques with the highest rockfall rates also have the highest rates of glacial erosion. The limited data also indicate that large south-facing glaciers have the highest erosion rates. The low erosion rates (8 to 76 mm. 1000 yr–1) suggest that 2 million to 14 million years were required to erode the cirques, and/or the erosion rates have not been constant.