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EARTH SCIENCE > Cryosphere > Glaciers/Ice Sheets > Glacier Thickness/Ice Sheet Thickness

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  • The dataset lists information about the instrumentation of boreholes drilled into Khumbu Glacier, Nepal. Boreholes were drilled in May 2017 and May 2018 to investigate the internal properties of Khumbu Glacier, specifically ice thickness, temperature, deformation and structure, as part of the NERC-funded ''EverDrill'' research project. The information provided includes each borehole''s ID, length, location, elevation and instrumentation, including the type and depth of each sensor. Funding was provided by the NERC grant NE/P00265X/1 and NE/P002021/1.

  • Model output from a series of idealised ice shelf-ocean simulations, demonstrating a new synchronously coupled modelling method as well as the response of ice shelf buttressing to melt under various temperature forcings.

  • The data set was produced for the work detailed in ''The response of ice sheets to climate variability'' by K Snow et al (2017, Geophys Research Letters). A coupled ice sheet-ocean model is configured in an idealised setting with an inland-deepening bedrock, forced by far-field hydrographic profiles representative of the Amundsen Sea continental shelf. Similar to observed variability, the thermocline depth in the far-field is moved up and down on various times scales as detailed in the publication, with periods ranging from 2 to ~50 years. Bedrock elevation is provided, and annual melt rate and ice thickness (or sub-annual for short time scales) is provided as well for each forcing period. In addition, similar experiments were carried out with an ice-only model with parameterised forcing. These outputs are provided too.

  • The survey collected a total of 11,500 km of data along 22 lines, spaced 12 km apart and oriented perpendicular to the strike of both the Bouguer anomaly field, as derived from land data (McGibbon and Smith, 1991), and the major sub-ice topographical features (Doake et al., 1983). The speed of the aircraft was set to produce a sample spacing of about 60 m and the data were collected at heights between 1600 and 2000 m above sea level. The gravity signal was recorded using a LaCoste and Romberg air/sea gravimeter, S-83, which has been kindly loaned to BAS by the Hydrographic Office of the Royal Navy. The meter was modified by the ZLS company for use in an aircraft. The equipment was deployed in a BAS De-Havilland Twin Otter aircraft. Differential, dual frequency, carrier phase, GPS measurements of the aircraft''s motion were made using Trimble and Ashtech geodetic receivers and antennas. Ice thickness data were obtained using a BAS-built, radio echo sounding system (Corr and Popple, 1994). Ice-bottom returns over most of the survey area were obtained at a sample spacing of approximately 28 m. GPS measurements were tied into base stations in International Terrain Reference Frame network (Dietrich et al., 1998) and gravity measurements to base stations in the IGSN71 net (Jones and Ferris, 1999). We present here the processed bed elevation picks from airborne radar depth sounding collected using the BAS PASIN radar system. Data are provided as XYZ ASCII line data.

  • The dataset lists information about boreholes drilled by hot water into Khumbu Glacier, Nepal. Boreholes were drilled in May 2017 and May 2018 to investigate the internal properties of Khumbu Glacier, specifically ice thickness, temperature, deformation and structure, as part of the NERC-funded ''EverDrill'' research project. The information provided includes each borehole''s ID, length, location (at the time of drilling), elevation and instrumentation. Funding was provided by the NERC grant NE/P00265X/1 and NE/P002021/1.

  • The output of a 40-year coupled ice-ocean run of Smith Glacier, the adjoining Dotson and Crosson ice shelves, and the nearby continental shelf, with ocean boundary conditions forced with a climatology downscaled from a regional model of the Amundsen Sea. Funding was provided by the NERC Standard Grant NE/M003590/1 - Is ice loss from West Antarctica driven by ocean forcing or ice and ocean feedbacks?

  • An airborne radar survey was flown as part of the GRADES-IMAGE project funded by BAS over the Antarctic Peninsula, Ellsworth Mountains and Filchner-Ronne Ice Shelf (also including the Evans Ice stream and Carson Inlet) mainly to image englacial layers and bedrock topography during the 2006/07 field season. Operating from temporary field camps at Sky Blu, Partiot Hills and out of RABID depot (Rutford Ice Stream), we collected ~27,550 km of airborne radio-echo sounding data over 100 hours of surveying. Our aircraft was equipped with dual-frequency carrier-phase GPS for navigation, radar altimeter for surface mapping, wing-tip magnetometers, and an ice-sounding radar system (PASIN). Note that there was no gravimetric element to this survey. We present here the full radar dataset consisting of the deep-sounding chirp and shallow-sounding pulse-acquired data in their processed form, as well as the navigational information of each trace, the surface and bed elevation picks, ice thickness, and calculated absolute surface and bed elevations. This dataset comes primarily in the form of NetCDF and georeferenced SEGY files. To interactively engage with this newly-published dataset, we also created segmented quicklook PDF files of the radar data.

  • We present here Bedmap2 (2013), a suite of gridded products describing surface elevation, ice-thickness and the sea floor and subglacial bed elevation of the Antarctic south of 60deg S. We derived these products using data from a variety of sources, including many substantial surveys completed since the original Bedmap compilation (Bedmap1) in 2001. In particular, the Bedmap2 ice thickness grid is made from 25 million measurements, over two orders of magnitude more than were used in Bedmap1. In most parts of Antarctica the subglacial landscape is visible in much greater detail than was previously available and the improved data coverage has in many areas revealed the full scale of mountain ranges, valleys, basins and troughs, only fragments of which were previously indicated in local surveys. The derived statistics for Bedmap2 show that the volume of ice contained in the Antarctic ice sheet (27 million km3) and its potential contribution to sea-level rise (58 m) are similar to those of Bedmap1, but the mean thickness of the ice sheet is 4.6 % greater, the mean depth of the bed beneath the grounded ice sheet is 72 m lower and the area of ice sheet grounded on bed below sea level is increased by 10 %. The Bedmap2 compilation highlights several areas beneath the ice sheet where the bed elevation is substantially lower than the deepest bed indicated by Bedmap1. These products, along with grids of data coverage and uncertainty, provide new opportunities for detailed modelling of the past and future evolution of the Antarctic ice sheets. The associated Bedmap datasets are listed here: https://www.bas.ac.uk/project/bedmap/#data The compilation of Bedmap2 products was undertaken within the British Antarctic Survey''s programme, Polar Science for Planet Earth.

  • This dataset consists of measurements of cosmogenic Be-10 and Al-26 in quartz for a set of cobbles collected from a moraine proximal to Mount Murphy, a nunatak located between Pope and Thwaites glaciers, West Antarctica. The cobbles were collected during the 2015-2016 Antarctic field season. The dataset includes cosmogenic nuclide (Be-10 and Al-26) surface exposure ages and all field (location, elevation, shielding, thickness) and analytical laboratory (quartz, beryllium and aluminium carrier masses, Be-10/Be-9 and Al-26/Al-27 ratios) data for field samples and procedural blanks required to calculate the ages. Funding source: Natural Environment Research Council (NERC: Grants NE/S006710/1 (JSJ), NE/K012088/1 (JSJ), NE/S006753/1 (DHR), NE/K011278/1 (DHR)). Australian Nuclear Science and Technology Organisation (ANSTO) Centre for Accelerator Science award AP12872 (DHR) through the National Collaborative Research Infrastructure Strategy (NCRIS).

  • A British Antarctic Survey Twin Otter and survey team acquired 8,300 line-km of aerogeophysics data during the Austral summer of 1998/99. Gravity and radio-echo data were acquired simultaneously with the magnetic data at a compromise constant barometric height of 2,200 m, which provides a terrain clearance of 100 m over the highest peaks. Two separate surveys were conducted; one at 5 km line spacing (tie lines at 20 km) over and stretching beyond the southern extent of the Forrestal range (main survey), and one at 2 km line spacing (tie lines at 8 km) covering the Dufek Massif (detailed survey). Ashtech Z12 dual frequency GPS receivers were used for survey navigation. Pseudorange data were supplied to a Picodas PNAV navigation interface computer, which was used to guide the pilot along the pre-planned survey lines. The actual flight path was recovered, using carrier-phase, continuous, kinematic GPS processing techniques. All pseudorange navigation data were recorded at 1 Hz on a Picodas PDAS 1000, PC-based data acquisition system. We present here the processed bed elevation picks from airborne radar depth sounding collected using the "BAS-built" radar system (Corr and Popple, 1994; Fremand, Bodart et al., 2022), which used a 4 us linear frequency modulated pulse in addition to a standard short 0.25 us pulse Data are provided as XYZ ASCII line data.