Authors

Student Authors:

Keyleigh Wallick '20, Gettysburg College

Faculty Co-Author:

Sarah Principato, Environmental Studies

Class Year

2020

Document Type

Article

Date of Creation

7-26-2020

Department 1

Environmental Studies

Abstract

This study presents the first analysis of ice‐free cirques on the Faroe Islands using a Geographical Information System (GIS) and the Automated Cirque Metric Extraction (ACME) tool. The length, width, area, circularity, mean aspect, mean slope, and elevation range, minimum, and maximum were calculated using ACME. Cirque distance to coastline was measured using ArcGIS. A total of 116 cirques were identified. Mean cirque length is 950 m and mean cirque width is 890 m. Average cirque area is 0.8 km2 and mean elevation is 386 m a.s.l. The modal orientation of the aspect of cirques is north‐northeast, with a vector mean of 7° and mean resultant length of 0.09. Aspect data have large dispersion, which shows evidence of cloudy ablation seasons in the past. The dispersion in aspect may also be related to the time transgressive nature of glacier occupation in these cirques. Past equilibrium‐line altitudes (ELAs) of cirque glaciers reconstructed with the minimum point method resulted in a mean palaeo‐ELA of 213 m a.s.l. Positive, linear relationships are observed between palaeo‐ELA and cirque distance to coastline. There are at least two possible interpretations of this relationship: (i) that the cirque formation is dependent on pre‐existing topography with cirques forming at the head of valleys, which occurs at higher elevations further inland, and (ii) that this relationship demonstrates the importance of access to moisture for glacier survival. A combination of both interpretations is also possible. Positive linear relationships are also observed between longitude and palaeo‐ELA indicative of palaeo‐precipitation patterns along an east–west gradient. Cirques on the Faroe Islands are smaller in length and width and present at lower elevations compared to cirques located in other regions of the world. The timing of glacial occupation in these cirques is not known, and the landforms likely formed over multiple glaciations.

Required Publisher's Statement

This is the peer reviewed version of the following article: Wallick, K. N. & Principato, S. M. 2020: Quantitative analyses of cirques on the Faroe Islands: evidence for time transgressive glacier occupation. Boreas, Vol. 49, pp. 828– 840., which has been published in final form at https://doi.org/10.1111/bor.12458. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.

Available for download on Monday, July 26, 2021

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