DOI: 10.5281/zenodo.3749316
title: Data associated with 'Processes at the margins of supraglacial debris cover: quantifying dirty ice ablation and debris redistribution'

description: Data associated with Fyffe, C. L., Woodget, A. S., Kirkbride, M. P., Deline, P., Westoby, M. J. and Brock, B. W. (2020) Processes at the margins of supraglacial debris cover: quantifying dirty ice ablation and debris redistribution, Earth Surface Processes and Landforms, doi:10.1002/esp.4879. The file All_quadrat_data_Z contains the data associated within each of the quadrats which were positioned on the ice surface. Some of the values are extracted from the UAV derived data within the area of the quadrat, while other data is based on measurements from the ground truth images (taken at ground level). The main data types are given below. The data sub-types and units are given in the file header. Quadrat: Quadrat name Elevation: Elevation from the UAV DEM Aspect: Aspect from the UAV DEM Ablation: Ablation derived from the UAV products (see the paper for details) Albedo: Measured albedo Rock_stats_image: Statistics on the clasts sampled from the ground truth image of the quadrat Debris_cover: Percentage debris cover derived from both the ground truth image (point) and UAV derived orthophotos Rock_stats_meas: Statistics on the clasts measured in the field The file Feature_Tracking_Data_Z contains data on clast movement, derived by locating the same clasts in the July and August orthophotos. The August orthophoto location was corrected for ice flow. The main data types are given below. The data sub-types and units are given in the file header. Coordinates: Locations of the points on the clasts in the July and August orthophotos Elevation: Elevation from the UAV derived DEMs Slope_from_slope_map: Slope from the UAV derived DEMs Surface: Either dirty ice (partial debris cover, or debris (continuous cover) Clast_length: A-axis length of the tracked clast Track_lines_stats: Characteristics of the line joining the clast locations Clast_velocity: Velocity of the tracked clast. Note the velocities derived from the distance measured over the surface were used for the analysis in the paper. The file Profiles_Data_Z contains the elevation and ablation data extracted following four cross-profiles which crossed the study area. Tables are also included giving the calculated moraine slope gradients and their change over time. The main data types are: Distance: The distance along the cross-section Elevation: The elevation from either the July or August DEM Ablation: The ablation value from the map of spatially continuous ablation. The folder GIS_Data_Z contains a range of GIS data associated with the paper. Included in the Zip file is an ArcMap document 'GIS_Data_Dirty_Ice' which includes all the data, along with a Word document ('Metadata for GIS data') which describes each of the files included within the ArcMap document. Briefly, the included data covers ground truth data (georeferenced ground truth photos, sample points and their classification, clast sizes, quadrat georeferencing information), clast track data (over the study area and the small scale clast tracks), stake data (measured and modelled ablation, calculated horizontal velocities and combined slope and emergence values), mapped ablation, percentage debris cover (and the difference in percentage cover), orthophotos, elevation data (and the cross-sections used to extract this) and the boundaries between the dirty and debris-covered ice. All data sets are in the WGS 1984 UTM Zone 32N coordinate system. The folder Percent_Debris_Analysis_H_Z contains the data used to derive Figure 5 (ablation and percentage debris cover data) in Matlab format (.mat file). It also includes the code used to make the figure. More details on file names will not be given here as the code documents the analysis steps. If any further information is required about the data then please get in contact with Catriona Fyffe.
description: We would like to thank the British Society for Geomorphology for funding this work and the NERC Geophysical Equipment Facility (loan 1087) for providing the loan of two dGPS receivers. The authors are also grateful to Gwilym Luckett (employed through the University of Worcester VRAS scheme), John Barrow (supported by the University of Worcester), Amelia Andrews and Fiona White for their invaluable help in the field. We also thank the team of the Fondazione Montagna Sicura for their assistance during the August field trip.