Further by downloading this data the user acknowledges that they agree with the NERC data policy (), and the following conditions:

1. To cite the data in any publication as follows:

Corr, H. (2020). Processed bed elevation picks from airborne radar depth sounding across the Evans Ice Stream, Southern Palmer Land (1994/95 season) (Version 1.0) [Data set]. UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation. https://doi.org/10.5285/2C261013-9A0E-447D-A5BB-B506610B14FF

2. The user recognizes the limitations of data. Use of the data is at the users' own risk, and there is no warranty as to the quality or accuracy of any data, or the fitness of the data for your intended use. The data are not necessarily fully quality assured and cannot be expected to be free from measurement uncertainty, systematic biases, or errors of interpretation or analysis, and may include inaccuracies in error margins quoted with the data.

Methodology:

Data provided here includes picked ice sheet bed elevation along main line sections of the survey grid. Ice thickness data were obtained using a BAS-built, radio echo sounding system (Corr and Popple, 1994). No data from turns is included.

Note that one example of overlapping, or close proximity flight lines exists and contrasting bed elevation data exists on tow line segments. Bed elevation data on L541 was deemed inaccurate and is excluded from gridding

Channel description:

Basic Channels Name Description

Lon Longitude WGS 1984

Lat Latitude WGS 1984

x x projected meters*

y y projected meters*

Radar

surfElev Surface elevation. BEDMAP2 surface used here.

bedElev Ice bed elevation, derived by subtracting tice from surfElev

tIce Ice thickness.

*Projected coordinates (x and y) are in Polar sterographic defined as follows:

Latitude of natural origin: -71

Longitude of natural origin: 0

Scale factor at natural origin: 0.994

False easting 0

False northing 2082760.109

Positioning for the Evans ice stream survey uses kinematic differential GPS. Processing was carried out using GPSurvey® software. Differential positioning used fixed base stations at each of the operational camps (Jones et al., 2002). Positions are calculated for the phase centre of the aircraft antenna. All positions (Lat, lon and height) are referred to the WGS1984 ellipsoid.