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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.

  • 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 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?

  • 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 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.

  • 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.

  • This dataset contains bed and surface elevation picks derived from airborne radar collected in 2015/16 over Foundation Ice Stream and Filchner Ice Shelf as part of the 5-year Filchner Ice Shelf System (FISS) project funded by NERC (grant reference number: NE/L013770/1) and awarded to the British Antarctic Survey with contribution from the National Oceanography Centre, the Met Office Hadley Centre, University College London, the University of Exeter, Oxford University, and the Alfred Wenger Institute. The aim of this project was to investigate how the Filchner Ice Shelf might respond to a warmer world, and what the impact of sea-level rise could be by the middle of this century. This collaborative initiative collected ~7,000 line-km of new aerogeophysical data using the 150MHz PASIN radar echo sounding system (Corr et al., 2007) deployed on a British Antarctic Survey (BAS) Twin Otter.

  • This data set corresponds to the processing of data acquired by the British Antarctic Survey (BAS) airborne Synthetic Aperture Radar (SAR) PASIN2 (Polarimetric Airborne Scientific INstrument, mark 2), designed for deep ice sounding and basal 3D-mapping. The dataset includes the processed calibration data collected over the sea surface near Rothera Research Station during the Antarctic Summers campaigns in 2016/17 FISS (Filchner Ice Shelf System) and 2019/20 BEAMISH (Bed Access, Monitoring and Ice Sheet History) projects, and the processed SAR images as depth profiles in the Recovery Ice Stream near its grounding line, in 2016/17 (FISS). With multiple antennas for transmission and reception at 150-MHz central frequency, and an across-track physical array, PASIN2 resolves the ambiguities for distinguishing between scatterers from port and starboard directions. After processing several 2D SAR images (range and along-track dimensions) with transmitter-receiver pairs, the directional ambiguities are resolved, obtaining the across-track Direction of Arrival (DoA, elevation angle) estimation. Finally, from the 3D geometry of range, along-track and across-track angle, the real depths and across-track distances are estimated, regarding the case of the incorrectly assumed vertical DoA of a single SAR image. The calibration flights assessed and validated the instrument antenna patterns and processing performances. In this dataset, only the simulated and measured antenna patterns, and SAR and DoA images are included. By resolving directional ambiguities and accounting for reflector across-track location, the true ice thickness and bed elevation are obtained, thereby removing the error of the usual assumption of vertical DoA, that greatly influence the output of flow models of ice dynamics. This work was supported by NERC grant reference NE/L013444/1.

  • SAR-processed two-dimensional radargram data in SEG-Y format acquired from the Institute and Moller ice streams, West Antarctica between mid-December 2010 and mid-January 2011. Data were collected using the British Antarctic Survey (BAS) Polarimetric radar Airborne Science Instrument (PASIN) radar, operated at a centre frequency of 150 MHz, and installed on the BAS Twin Otter aircraft "Bravo Lima". In total, ~25,000km of aerogeophysical data were collected, with coverage extending from the ice stream grounding zone to the ice divide. A high-resolution grid, with a line-spacing of 7.5 x 25 km, was acquired over the central parts of the ice stream catchments. Data were acquired during twenty-eight survey flights (sixteen flown from remote field camp C110, ten from Patriot Hills and two "transit" flights). Funding for this data acquisition was provided by the UK NERC AFI grant NE/G013071/1. These data should be cited as follows: Siegert, Martin et al. (2017); Synthetic-aperture radar (SAR) processed airborne radio-echo sounding data from the Institute and Moller ice streams, West Antarctica, 2010-11; Polar Data Centre, Natural Environment Research Council, UK; doi:10.5285/8a975b9e-f18c-4c51-9bdb-b00b82da52b8

  • Three separate airborne radar surveys were flown during the austral summer of 2016/17 over the Filchner Ice Shelf and Halley Ice Shelf (West Antarctica), and over the outlet glacier flows of the English Coast (western Palmer Land, Antarctic Peninsula) during the Filchner Ice Shelf System (FISS) project. This project was a NERC-funded (grant reference number: NE/L013770/1) collaborative initiative between the British Antarctic Survey, the National Oceanography Centre, the Met Office Hadley Centre, University College London, the University of Exeter, Oxford University, and the Alfred Wenger Institute to investigate how the Filchner Ice Shelf might respond to a warmer world, and what the impact of sea-level rise could be by the middle of this century. The 2016/17 aerogeophysics surveys acquired a total of ~26,000 line km of aerogeophysical data. The FISS survey consisted of 17 survey flights totalling ~16,000 km of radar data over the Support Force, Recovery, Slessor, and Bailey ice streams of the Filchner Ice Shelf. The Halley Ice Shelf survey consisted of ~4,600 km spread over 5 flights and covering the area around the BAS Halley 6 station and the Brunt Ice Shelf. The English Coast survey consisted of ~5,000 km spread over 7 flights departing from the Sky Blu basecamp and linking several outlet glacier flows and the grounding line of the western Palmer Land, including the ENVISAT, CRYOSAT, GRACE, Landsat, Sentinel, ERS, Hall, Nikitin and Lidke ice streams. Our Twin Otter aircraft was equipped with dual-frequency carrier-phase GPS for navigation, radar altimeter for surface mapping, wing-tip magnetometers, an iMAR strapdown gravity system, and a new ice-sounding radar system (PASIN-2). 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.