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  • 1
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    Seismic reflection data of a basal channel and ocean cavity at the ice shelf-grounding line area of Support Force Glacier, Filchner Ice Shelf, Antarctica (2021)
    PANGAEA
    Details
    Publication Date: 2024-04-20
    Description: Support Force Glacier (SFG) is a large ice stream feeding into the Filchner Ice Shelf. The active seismic survey is recorded at the sheet-shelf transition of SFG. We map the bed while grounded, the ocean cavity around a surface channel at the ice shelf and its counterpart at the base, the basal channel, and the seabed. The survey consists of 5 seismic reflection profiles, 2 along-flow profiles and 3 across-flow profiles. The 2.42GB seismic data were recorded with a 300 m long streamer consisting of 96 30Hz p-wave sensors. The sample rate is 0.5 ms, record length 3000 ms. The data is single fold, shot spacing is 150 m: line name: profile TC paper: direction: #shots: - 20170501 profile I along-flow 291 shots - 20170502 profile III across-flow 28 shots - 20170503 profile II along-flow 71 shots - 20170504 profile IV across-flow 40 shots - 20170506 profile V across-flow 50 shots Presented are for each line (20170501 used as example): - The raw shots: 20170501_RAW_SHOTS_EDITS_GEOM.segy - The Kirchhoff migrated and depth converted profiles: 20170501stat_TXmig_Zconv.segy - The shot x,y,z coordinates in longitude, latitude and surface height in meters above sea level (z, WGS84 ellipsoid): 20170501_GPS.txt
    Keywords: 300 m snow streamer with 96 gimballed 30 Hz vertical compressional wave (P-wave) sensors; ANT-Land_2016/17_FISP; AWI Antarctic Land Expedition; Binary Object; Binary Object (File Size); Event label; Filchner Ice Shelf Project; File content; FISP; FISP_2016-2017_20170501; FISP_2016-2017_20170502; FISP_2016-2017_20170503; FISP_2016-2017_20170504; FISP_2016-2017_20170506; Ice-shelf Channels; profile I; profile II; profile III; profile IV; profile V; Snow streamer; SSTREAM
    Type: Dataset
    Format: text/tab-separated-values, 54 data points
    Location Call Number Limitation Availability
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    DATA PANGAEA
  • 2
    Electronic Resource
    Electronic Resource
    Distortion of isochronous layers in ice revealed by ground-penetrating radar (1999)
    [s.l.] : Macmillan Magazines Ltd.
    Nature 398 (1999), S. 323-326 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] In addition to measuring ice-sheet thickness, ground-penetrating radar can be used to delineate reflections in ice sheets. These reflections are generally accepted to result from layers of isochronous deposition of snow and can reveal much about the dynamics of the ice flow. Here we ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/18653
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    Paper (German National Licenses)
    Fulltext
  • 3
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    High-resolution boundary conditions of an old ice target near Dome C, Antarctica (2018)
    Details
    Publication Date: 2020-10-13
    Description: A high-resolution (1 km line spacing) aerogeophysical survey was conducted over a region near the East Antarctic Ice Sheet’s Dome C that may hold a 1.5 Myr climate record. We combined new ice thickness data derived from an airborne coherent radar sounder with unpublished data that was in part unavailable for earlier compilations, and we were able to remove older data with high positional uncertainties. We generated a revised high-resolution digital elevation model (DEM) to investigate the potential for an old ice record in this region, and used laser altimetry to confirm a Cryosat-2 derived DEM for inferring the glaciological state of the candidate area. By measuring the specularity content of the bed, we were able to find an additional 50 subglacial lakes near the candidate site, and by Doppler focusing the radar data, we were able to map out the roughness of the bed at length scales of hundreds of meters. We find that the primary candidate region contains elevated rough topography interspersed with scattered subglacial lakes and some regions of smoother bed. Free subglacial water appears to be restricted from bed overlain by ice thicknesses of less than 3000 m. A site near the ice divide was selected for further investigation. The high resolution of this ice thickness data set also allows us to explore the nature of ice thickness uncertainties in the context of radar geometry and processing.
    Description: Published
    Description: 1897-1911
    Description: 5A. Paleoclima e ricerche polari
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Limitation Availability
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    PAPER (OA)
  • 4
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    Comparison of measurements from different radio-echo sounding systems and synchronization with the ice core at Dome C, Antarctica (2017)
    COPERNICUS GESELLSCHAFT MBH
    In:  EPIC3The Cryosphere, COPERNICUS GESELLSCHAFT MBH, 11(1), pp. 653-668, ISSN: 1994-0416
    Details
    Publication Date: 2017-10-17
    Description: We present a compilation of radio-echo sounding (RES) measurements of five radar systems (AWI, BAS, CReSIS, INGV and UTIG) around the EPICA Dome C (EDC) drill site, East Antarctica. The aim of our study is to investigate the differences of the various systems in their resolution of internal reflection horizons (IRHs) and bed topography, penetration depth, and capacity of imaging the basal layer.We address the questions of the compatibility of existing radar data for common interpretation, and the suitability of the individual systems for reconnaissance surveys. We find that the most distinct IRHs and IRH patterns can be identified and transferred between most data sets. Considerable differences between the RES systems exist in range resolution and depiction of the bottom-most region. Considering both aspects, which we judge as crucial factors in the search for old ice, the CReSIS and the UTIG systems are the most suitable ones. In addition to the RES data set comparison we calculate a synthetic radar trace from EDC density and conductivity profiles. We identify ten common IRHs in the measured RES data and the synthetic trace. Then we conduct a sensitivity study for which we remove certain peaks from the input conductivity profile. As a result the respective reflections disappear from the modeled radar trace. In this way, we establish a depth conversion of the measured travel-times of the IRHs. Furthermore, we use these sensitivity studies to investigate the cause of observed reflections. The identified IRHs are assigned ages from the EDC’s time scale. Due to the isochronous character of these conductivity-caused IRHs, they are a means to extend the Dome C age structure by tracing the IRHs along the RES profiles.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Limitation Availability
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    PAPER (OA)
  • 5
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    Radio-echo sounding measurements and ice-core synchronization at Dome C, Antarctica (2018)
    Details
    Publication Date: 2018-03-09
    Description: We present a compilation of radio-echo sounding (RES) measurements of five radar systems (AWI, BAS, CReSIS, INGV and UTIG) around the EPICA Dome C (EDC) drill site, East Antarctica. The aim of our study is to investigate the differences of the various systems in their resolution of internal reflection horizons (IRHs) and bedrock topography, penetration depth, and quality of imaging the basal layer. We address the questions of the compatibility of existing radar data for common interpretation, and the 5 suitability of the individual systems for Oldest Ice reconnaissance surveys.We find that the most distinct IRHs and IRH patterns can be identified and transferred between most data sets. Considerable differences between the RES systems exist in range resolution and depiction of the basal layer. Considering both aspects, which we judge as crucial factors in the search for old ice, the CReSIS and the UTIG systems are the most valuable ones. In addition to the RES data set comparison we calculate a synthetic radar trace from EDC density and conductivity profiles.We identify ten common IRHs in the measured 10 RES data and the synthetic trace. The reflection-causing conductivity sections are determined by sensitivity studies with the synthetic trace. In this way, we accomplish an accurate two-way travel time to depth conversion for the reflectors, without having to use a precise velocity-depth function that would accumulate depth uncertainties with increasing depth. The identified IRHs are assigned with the AICC2012 time scale age. Due to the isochronous character of these conductivity-caused IRHs, they are a means to extend the Dome C age structure by tracing the IRHs along the RES profiles.
    Description: Published
    Description: 653-668
    Description: 5A. Paleoclima e ricerche polari
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Limitation Availability
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    PAPER (OA)
  • 6
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    Comparison of measurements from different radio-echo sounding systems and synchronization with the ice core at Dome C, Antarctica (2018)
    Details
    Publication Date: 2018-05-04
    Description: We present a compilation of radio-echo sounding (RES) measurements of five radar systems (AWI, BAS, CRe-SIS, INGV and UTIG) around the EPICA Dome C (EDC) drill site, East Antarctica. The aim of our study is to investigate the differences of the various systems in their resolution of internal reflection horizons (IRHs) and bed topography, penetration depth and capacity of imaging the basal layer. We address the questions of the compatibility of existing radar data for common interpretation and the suitability of the individual systems for reconnaissance surveys. We find that the most distinct IRHs and IRH patterns can be identified and transferred between most data sets. Considerable differences between the RES systems exist in range resolution and depiction of the bottom-most region. Considering both aspects, which we judge as crucial factors in the search for old ice, the CReSIS and the UTIG systems are the most suitable ones. In addition to the RES data set comparison we calculate a synthetic radar trace from EDC density and conductivity profiles. We identify 10 common IRHs in the measured RES data and the synthetic trace. We then conduct a sensitivity study for which we remove certain peaks from the input conductivity profile. As a result the respective reflections disappear from the modeled radar trace. In this way, we establish a depth conversion of the measured travel times of the IRHs. Furthermore, we use these sensitivity studies to investigate the cause of observed reflections. The identified IRHs are assigned ages from the EDC’s timescale. Due to the isochronous character of these conductivity-caused IRHs, they are a means to extend the Dome C age structure by tracing the IRHs along the RES profiles.
    Description: Published
    Description: 653-668
    Description: 5A. Paleoclima e ricerche polari
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Limitation Availability
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    PAPER (OA)
  • 7
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    Basal melt of the southern Filchner Ice Shelf, Antarctica (2022)
    Copernicus Publications
    In:  EPIC3The Cryosphere, Copernicus Publications, 16, pp. 1469-1482
    Details
    Publication Date: 2022-05-09
    Description: Basal melt of ice shelves is a key factor governing discharge of ice from the Antarctic Ice Sheet as a result of its effects on buttressing. Here, we use radio echo sounding to determine the spatial variability of the basal melt rate of the southern Filchner Ice Shelf, Antarctica, along the inflow of Support Force Glacier. We find moderate melt rates with a maximum of 1.13 m/a about 50 km downstream of the grounding line. The variability of the melt rates over distances of a few kilometres is low (all but one 〈0.15 m/a at 2 km distance), indicating that measurements on coarse observational grids are able to yield a representative melt rate distribution. A comparison with remote-sensing-based melt rates revealed that, for the study area, large differences were due to inaccuracies in the estimation of vertical strain rates from remote sensing velocity fields. These inaccuracies can be overcome by using modern velocity fields.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
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  • 8
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    Antarctic Bedmap data: Findable, Accessible, Interoperable, and Reusable (FAIR) sharing of 60 years of ice bed, surface, and thickness data (2024)
    Egu-Copernicus
    Details
    Publication Date: 2024-01-11
    Description: One of the key components of this research has been the mapping of Antarctic bed topography and ice thickness parameters that are crucial for modelling ice flow and hence for predicting future ice loss and the ensuing sea level rise. Supported by the Scientific Committee on Antarctic Research (SCAR), the Bedmap3 Action Group aims not only to produce new gridded maps of ice thickness and bed topography for the international scientific community, but also to standardize and make available all the geophysical survey data points used in producing the Bedmap gridded products. Here, we document the survey data used in the latest iteration, Bedmap3, incorporating and adding to all of the datasets previously used for Bedmap1 and Bedmap2, including ice bed, surface and thickness point data from all Antarctic geophysical campaigns since the 1950s. More specifically, we describe the processes used to standardize and make these and future surveys and gridded datasets accessible under the Findable, Accessible, Interoperable, and Reusable (FAIR) data principles. With the goals of making the gridding process reproducible and allowing scientists to re-use the data freely for their own analysis, we introduce the new SCAR Bedmap Data Portal (https://bedmap.scar.org, last access: 1 March 2023) created to provide unprecedented open access to these important datasets through a web-map interface. We believe that this data release will be a valuable asset to Antarctic research and will greatly extend the life cycle of the data held within it. Data are available from the UK Polar Data Centre: https://data.bas.ac.uk (last access: 5 May 2023​​​​​​​). See the Data availability section for the complete list of datasets.
    Description: Published
    Description: 2695–2710
    Description: OSA2: Evoluzione climatica: effetti e loro mitigazione
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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