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  • 1
    Publication Date: 2017-04-04
    Description: Precise topography from European Remote-sensing Satellite radar altimetry and high density of airborne radio-echo sounding in the area surrounding Dome C, Antarctica, show a link between surface features and subglacial lakes. In this paper, we extend the study to fine structures by computing a curvature-based coefficient (cy) related to surface undulations. These coefficient variations reveal many surface undulations, and some elongated features of this parameter seem to link known subglacial lakes. A population of high values of this coefficient, assumed to correspond to transitions between sliding and non-sliding flow regime, strengthen the appearance of a network which would link most of the lakes in the area. The existence of such a network impacts on ice-flow dynamics and on subglacial-lake studies.
    Description: Published
    Description: 252-256
    Description: 3.8. Geofisica per l'ambiente
    Description: JCR Journal
    Description: reserved
    Keywords: Ice sheet ; Subglagial lakes ; 02. Cryosphere::02.02. Glaciers::02.02.03. Geomorphology ; 02. Cryosphere::02.02. Glaciers::02.02.04. Ice ; 02. Cryosphere::02.02. Glaciers::02.02.05. Ice dynamics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 2
    Publication Date: 2017-04-04
    Description: Improved knowledge of geometrical boundary conditions, such as bedrock geometry and surface topography, can contribute significantly to glaciological studies including ice-sheet-flow modelling. Precise thickness and altimetric data allow an estimation of ice-flow direction, the balance velocity and the basal shear stress. These parameters are calculated along a 1160 km profile in East Antarctica using a relationship between shear stress, basal temperature, the Glen flow exponent and a parameter related to strain rate. Strong variations of the flow-law parameters and basal conditions are found to play a major role in the ice-flow pattern. Sliding, anisotropy and longitudinal stress strongly perturb the validity of the law, but their signature can be identified.
    Description: Published
    Description: 102-106
    Description: 3.8. Geofisica per l'ambiente
    Description: JCR Journal
    Description: reserved
    Keywords: Ice sheet ; Mass balance ; Bedrock-topography ; 02. Cryosphere::02.02. Glaciers::02.02.03. Geomorphology ; 02. Cryosphere::02.02. Glaciers::02.02.04. Ice ; 02. Cryosphere::02.02. Glaciers::02.02.05. Ice dynamics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 3
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    Unknown
    International Glaciological Society
    Publication Date: 2017-04-04
    Description: The power strength of the radio-echo signal coming from reflecting sub-ice surfaces is used to determine the nature of the reflecting surface, i.e. rock, water or sea water. Electromagnetic analysis shows that the amplitude variations detected by radio-echo sounding are mainly due to the nature of the interface as well as the concave or convex shape of the reflectors. In this paper, some relevant profiles showing the power variations due to the different nature of the interface and the shape of the reflectors are presented. These results are important both for surface shape determination and for subglacial lake detection.
    Description: Published
    Description: 9-12
    Description: 3.8. Geofisica per l'ambiente
    Description: JCR Journal
    Description: reserved
    Keywords: Bedrock-topography ; Ice sheet ; 02. Cryosphere::02.02. Glaciers::02.02.03. Geomorphology ; 02. Cryosphere::02.02. Glaciers::02.02.04. Ice ; 02. Cryosphere::02.02. Glaciers::02.02.05. Ice dynamics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 4
    Publication Date: 2017-04-04
    Description: A large number of airborne and ground-based radar echo sounding (RES) data were collected in the Dome C - Vostok region during the Italian Antarctic expeditions in 1995, 1997, 1999 and 2001. Tabacco et al. (1998) used the 1995 data to produce a topographic map of Dome C. We present a new map of bed topography based on all collected radar data.
    Description: Published
    Description: Milan, 25-26 June 2002 / Dipartimento di Scienze Ambiente e Territorio (DISAT), Università di Milano Bicocca, P.zza della Scienza 1, 20126 Milano
    Description: 3.8. Geofisica per l'ambiente
    Description: open
    Keywords: East Antarctica ; RES system ; EPICA ; bedrock map ; 02. Cryosphere::02.02. Glaciers::02.02.02. Cryosphere/atmosphere Interaction ; 02. Cryosphere::02.02. Glaciers::02.02.05. Ice dynamics ; 02. Cryosphere::02.02. Glaciers::02.02.06. Mass balance ; 04. Solid Earth::04.02. Exploration geophysics::04.02.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Conference paper
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  • 5
    Publication Date: 2017-04-04
    Description: A new bedrock map of the Dome C area is presented, based on all radar data collected during Italian Antarctic Expeditions in 1995, 1997, 1999 and 2001. The map clearly distinguishes the Dome C plateau, along with valleys and ridges. The plateau develops at three different altimetric levels, and its morphology is characterized by hills and closed depressions. There are no visible features which can be ascribed to glacial erosion or deposition. The major valley is 15km wide and 500m deep; its axis is parallel to that of other valleys and ridges in the plateau. The valley bottom is not flat, but contains a saddle at its centre. The morphology of the major valley may be considered a relict one which was not modified by the overlying ice cap. Two large ridges, characterized by hills, saddles and depressions, lie near the boundaries of the area. The map is used to recalculate ice thickness below the European Project for Ice Coring in Antarctica (EPICA) borehole. The new thickness is 3300 m, 50m greater than before, implying that the expected palaeoclimate record from the ice core could extend back 〉800 kyr.
    Description: Published
    Description: 321-325
    Description: 3.8. Geofisica per l'ambiente
    Description: JCR Journal
    Description: reserved
    Keywords: Antarctica ; RES ; EPICA ; bedrock map ; 02. Cryosphere::02.02. Glaciers::02.02.05. Ice dynamics ; 02. Cryosphere::02.02. Glaciers::02.02.06. Mass balance ; 04. Solid Earth::04.02. Exploration geophysics::04.02.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 6
    Publication Date: 2019-11-04
    Description: Radio echo sounding measurements were collected during two Antarctic expeditions to determine the ice thickness and the sub-glacial morphology of Talos Dome in the region around 72°48'S; 159°06'E (about 6400 km2) on the edge of the East Antarctic plateau adjacent to Victoria Land in the western Ross Sea sector. The increasing interest in this region is due to the fact that in this area the ice accumulation is higher than in other sites in East Antarctica. Because of this, Talos Dome could be a new site for a project of a deep ice core drilling to obtain information on climate changes near the coast of Antarctica. In this frame, the knowledge of the bedrock topography is of great importance to choose the best location for the drilling site. In this paper, airborne radio echo sounding results from two Antarctic expeditions (1997 and 1999) are presented. Bedrock topography in bi- and three-dimensions for the Talos Dome region are discussed.
    Description: Published
    Description: JCR Journal
    Description: open
    Keywords: radio echo sounding ; radio glaciology ; ice thickness measurements ; 02. Cryosphere::02.03. Ice cores::02.03.09. Instruments and techniques ; 04. Solid Earth::04.02. Exploration geophysics::04.02.05. Downhole, radioactivity, remote sensing, and other methods
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 2708984 bytes
    Format: application/pdf
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  • 7
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    Unknown
    IEEE / Institute of Electrical and Electronics Engineers Incorporated
    Publication Date: 2017-04-04
    Description: Abstract—Geophysical surveys have played a fundamental role in glaciology, climatology, and geology studies conducted at and around the site of the EPICA Dome C Ice Core (Antarctica). Analysis of radio-echo sounding (RES) data collected during the 2009 and 2011 Italian Antarctic Expeditions, in the immediate vicinity (2 km) of the Core site, reveals the presence of small-scale bedrock structures. Data acquired during the 2011 campaign, which applied the latest updates of our instrument, show double echoes from the ice bottom separated by very small time intervals. These reflections are distributed close to the topographic dome and do not always correspond to particular features of the bedrock structure, but instead may correspond to small-scale subglacial water storage. The unprecedented spatial resolution of the basal environment for Dome C from these recent surveys allows us to identify this and other features that have been missed by previous larger scale RES surveys of this area.
    Description: Published
    Description: 1558 - 1564
    Description: 7A. Geofisica di esplorazione
    Description: JCR Journal
    Description: restricted
    Keywords: Bedrock ; Dome C ; EPICA ; reflectivity ; radio-echo sounding (RES) ; data analysis ; 02. Cryosphere::02.02. Glaciers::02.02.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 8
    Publication Date: 2019-11-04
    Description: During three Antarctic summer campaigns (1995/97/99) Radio Echo Sounding (RES) system data from some glacier ice tongues in the East Antarctic regions between Victoria Land and George V Land were collected. The morphology and structure of the bottom surfaces deduced from the electromagnetic interpretation of echo signal were observed. The bottom surfaces at the ice/water interface show either irregular or flat contours or both. Some ice tongues are nearly perfectly flat, others show clear signs of irregularities while three of them have good regular spaced rippled bottom surfaces. The latter structures are well-evident in the longitudinal traverse of the tongues, whereas the transversal paths do not show the same features. This particular shape of the bottom surfaces related to the ablation process and detachment mechanism could be interesting especially to determine some physical characteristics and the possible fracture points of the ice tongues.
    Description: JCR Journal
    Description: open
    Keywords: radio echo sounding ; radio glaciology ; glacier ice tongues ; 02. Cryosphere::02.02. Glaciers::02.02.03. Geomorphology ; 04. Solid Earth::04.02. Exploration geophysics::04.02.05. Downhole, radioactivity, remote sensing, and other methods
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 3461391 bytes
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  • 9
    Publication Date: 2019-11-04
    Description: Very high frequency deep radio sounding systems for ice thickness measurements are practically the only useful apparatuses for large scale radar flight surveys in polar regions. The morphology of the bottom surface of an Antarctic floating ice tongue, in the Ross Sea area, East Antarctica, was studied using the arrival times of signal echoes of the radio sounding system. The amplitude variations of radar signals from the reflecting surface were analyzed to determine the gain or the loss of the reflectors. Such surfaces show quasi-parabolic geometrical shapes at the ice/water interface with both concave and convex faces towards the sounding system. Electromagnetic analysis performed on radar echoes indicates that amplitude variations detected by the antenna are focusing or defocusing effects only due to the reflector's shape. A factor in the radar equation that represents the surface shape when coherent reflectors are involved is introduced. This factor allows us to determine more precisely the morphology and electromagnetic characteristics of the interface between the media investigated by means of radio echo sounding.
    Description: JCR Journal
    Description: open
    Keywords: radio echo sounding ; radio glaciology ; glacier ice tongues ; 04. Solid Earth::04.02. Exploration geophysics::04.02.05. Downhole, radioactivity, remote sensing, and other methods
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 2682872 bytes
    Format: application/pdf
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