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  • A map of changes in ice surface speed in metres/year for Thwaites Glacier, West Antarctica, between January 2012 and January 2021. Speeds based on feature tracking of satellite synthetic aperture radar data. The work was funded by NERC projects NE/P011365/1 and NE/S006605/1.

  • Polarimetric phase-sensitive radar measurements were collected at the Western Antarctic Ice Sheet (WAIS) Divide on the 25th and 26th December 2019. The measurements were conducted at 10 sites along a 6 km-long transect ~5-10 km northeast of the location of the WAIS Divide Deep Ice Core. At each site, a suite of four quadrature (quad-) polarimetric measurements were collected using an autonomous phase-sensitive radio echo sounder (ApRES) in a single-input single-output (SISO) configuration. The study is part of the Thwaites Interdisciplinary Margin Evolution (TIME) project of the International Thwaites Glacier Collaboration (ITGC), and is a collaboration between the United States National Science Foundation (NSF) and the United Kingdom Natural Environment Research Council (NERC). It was funded by UK Natural Environment Research Council (NERC) research grant NE/S006788/1 and USA National Science Foundation (NSF) research grant 1739027.

  • A time series of surface ice flow speed at a point on Thwaites Glacier, West Antarctica. The point is on grounded ice and is upstream of a sub-shelf cavity on the west flank of the fast-moving core of Thwaites Glacier. There are a total of 589 points. First column = yyyy-mm-dd, second column = speed in kilometres per year. The work was funded by NERC projects NE/P011365/1 and NE/S006605/1.

  • Glacial outlines of the APIS (Antarctica Peninsula Ice Sheet) for 1988, 2001, 2009. This is now incorporated into the GLIMS (Global Land Ice Measurements from Space) project.

  • This is distributed temperature sensing (DTS) data from a 1,043 m borehole drilled to the base of Sermeq Kujalleq (Store Glacier), Greenland, 28 km inland from the glacier terminus. The DTS system was installed on 5 July 2019, with recordings continuing until cable failure on 13 August 2019. The record resolution is ~0.65 m. This work was primarily funded and conducted as part of the European Research Council RESPONDER project (https://www.erc-responder.eu/) under the European Union''s Horizon 2020 research and innovation program (Grant 683043). Robert Law was supported by Natural Environment Research Council Doctoral Training Partnership studentships (Grant NE/L002507/1).

  • A dataset of ice-margin change (advance/recession) at the south-western sector of the Greenland Ice Sheet, comprising data from 3325 terrestrial, 439 lacustrine and 35 marine ice-margins respectively. The dataset also comprises measures of ice-marginal lake parameters including area and intersect (length of the lake - ice-margin interface). Measurements were made at approximately five year intervals (epochs) from 1987 to 2015. The ice sheet margin and adjacent ice-marginal lakes were delineated by applying the Normalised Difference Snow Index (NDSI) and the Normalised Difference Water Index (NDWI) respectively to Landsat TM, ETM+ and OLI scenes. Ice-margin changes were measured relative to a series of fixed reference points. The dataset was generated to facilitate comparison of changes at the disparate ice-marginal environments of the ice sheet and investigate temporal patterns of ice-margin recession. The dataset was created and processed by researchers in the School of Geography at the University of Leeds and the Institute of Integrative Biology at the University of Liverpool.

  • Thwaites Glacier, West Antarctica. A time series of 156 profiles of ice surface elevation along a flowline based on the mean flow direction. The flowline passes through a region of large elevation change that took place between 2014 and 2017. The work was funded by NERC projects NE/P011365/1 and NE/S006605/1.

  • We can learn about the flow of ice in Antarctica by evaluating the key parameters that control the flow speed. These parameters include the basal drag coefficient and the ice viscosity. They can be estimated by adjusting their values so that model velocities at the upper surface agree with satellite observations. This dataset was produced using inverse methods to obtain the parameter values. In this approach a cost function that describes the mismatch between model and satellite data is minimised iteratively by making small adjustments to the parameters at each iteration to improve the fit. The result is better information about the flow field in the Antarctic ice sheet. Once the flow field is available it can be used as an initial state from which begin temporally evolving simulations using the model. A number of different examples are included to show how varying different parameters alters the temporally evolving simulations. The contributing datasets used to constrain the model are listed by Arthern et al (2015) and Arthern and Williams (2017). Multidecadal model simulations span up to 100 years of simulation time. This work was funded by NERC standard grant NE/L005212/1.

  • A transect of cores was taken from shelf to deep sea west of the Antarctic Peninsula off Marguerite Bay using a 12 m RVS piston corer, box corer and BGS vibrocorer deployed from RSS James Clark Ross cruise JR71 (12 days sea-time in 2001-2002). Successful coring and examination of sediments now on and immediately beneath the sea floor, which provided the deforming bed of the former ice stream, enhanced our understanding of conditions beneath ice streams. Data was collected as part of a project was to reconstruct the Late Quaternary dynamics of the Antarctic Peninsula Ice Sheet in Marguerite Bay and to compare sedimentation and ice-rafted debris records with the Larsen Ice Shelf area, on the other side of the Antarctic Peninsula. The mapping of streamlined sedimentary bedforms on the outer shelf has allowed the dimensions of a former fast-flowing ice stream present at the Last Glacial Maximum to be defined. This, in turn, enabled estimates of the past magnitude of ice flow through this glacial system to be calculated.

  • Uncertainties in future sea level projections are dominated by our limited understanding of the dynamical processes that control instabilities of marine ice sheets. A valuable case to examine these processes is the last deglaciation of the British-Irish Ice Sheet. The Minch Ice Stream, which drained a large proportion of ice from the northwest sector of the British-Irish Ice Sheet during the last deglaciation, is well constrained, with abundant empirical data which could be used to inform, validate and analyse numerical ice sheet simulations. We use BISICLES, a higher-order ice sheet model, to examine the dynamical processes that controlled the retreat of the Minch Ice Stream. We simulate retreat from the shelf edge under constant "warm" surface mass balance and subshelf melt, to isolate the role of internal ice dynamics from external forcings. The model simulates a slowdown of retreat as the ice stream becomes laterally confined at a "pinning-point" between mainland Scotland and the Isle of Lewis. At this stage, the presence of ice shelves became a major control on deglaciation, providing buttressing to upstream ice. Subsequently, the presence of a reverse slope inside the Minch Strait produces an acceleration in retreat, leading to a "collapsed" state, even when the climate returns to the initial "cold" conditions. Our simulations demonstrate the importance of the Marine Ice Sheet Instability and ice shelf buttressing during the deglaciation of parts of the British-Irish Ice Sheet. Thus, geological data could be used to constrain these processes in ice sheet models used for projecting the future of our contemporary ice sheets. Funding was provided by the Natural Environment Research Council (NERC) SPHERES Doctoral Training Partnership (NE/L002574/1) with CASE support from the British Geological Survey.