ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    Lakes and subglacial hydrological networks around Dome C, East Antarctica (2008)
    International Glaciological Society
    Details
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 2
    facet.materialart.
    Unknown
    Influence of geometrical boundary conditions on the estimation of rheological parameters (2008)
    International Glaciological Society
    Details
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 3
    facet.materialart.
    Unknown
    Electromagnetic reflecting properties of sub-ice surfaces (2008)
    International Glaciological Society
    Details
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 4
    facet.materialart.
    Unknown
    A New Bedrock Map of the Dome C Area (2008)
    Terra Antartica Publication
    Details
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 5
    facet.materialart.
    Unknown
    Airborne radar survey above Vostok region, east-central Antarctica: ice thickness and Lake Vostok geometry (2008)
    International Glaciological Society
    Details
    Publication Date: 2017-04-04
    Description: During the 1999-2000 Italian Expedition, an airborne radar survey was performed along 12 transects across Lake Vostok, Antarctica, and its western and eastern margins. Ice thickness, subglacial elevation and the precise location of lake boundaries were determined. Radar data confirm the geometry derived from previous surveys, but with some slight differences. We measured a length of up to 260 km, a maximum width of 81 km and an area of roughly 14000 km2. Along the major axis, from north to south, the ice thickness varies from 3800 to 4250 m, with a decreasing gradient. From west to east the ice thickness is fairly constant, except for two narrow strips located on the western and eastern margins, where it increases with high thickening rate. Over the lake the surface elevation increases from 3476 m a.s.1. [south) to 3525 (north), with a decreasing gradient, while the lake surface elevation decreases from -315 to -750 m a.s.l., with a decreasing gradient (absolute value). The icesurface and lake-ceiling slopes suggest that the lake is in a state of hydrostatic equilibrium.
    Description: Published
    Description: 62-69
    Description: 3.8. Geofisica per l'ambiente
    Description: JCR Journal
    Description: reserved
    Keywords: subglacial lakes ; ice thickness ; RES system ; 02. Cryosphere::02.02. Glaciers::02.02.02. Cryosphere/atmosphere Interaction ; 02. Cryosphere::02.02. Glaciers::02.02.05. Ice dynamics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 6
    facet.materialart.
    Unknown
    New bedrock map of Dome C, Antarctica, and morphostructural interpretation of the area (2008)
    International Glaciological Society
    Details
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 7
    facet.materialart.
    Unknown
    Evidence of 14 New Subglacial Lakes in the Dome C-Vostok Area (2008)
    Terra Antartica Publication
    Details
    Publication Date: 2017-04-04
    Description: In the last few years subglacial lakes have been of great interest to the scientific community for various reasons. The lakes could be an unknown extreme habitat, which have been isolated from the terrestrial biosphere for a long time. They may have formed before the ice sheet and could perhaps reveal environmental conditions prior to its formation. Lastly, they may play a role in the current dynamics of the ice sheet. Strong radar reflections from the base of the ice sheet can generally be ascribed to either water-saturated basal sediments or subglacial lakes (Oswald & Robin, 1973). Based on radar data alone, the identification of lakes is possible if other features are present: flat and quite horizontal reflectors with nearly constant echo intensity and sharp edges similar to the margins of a catchment basin (Siegert et al., 1996; Siegert & Ridley, 1998; German & Siegert, 1999; Siegert, 2000; Tabacco et al., 2002). Subglacial lakes can be expressed in the overlying ice sheet as extremely flat surfaces with respect to the surrounding slopes (Ridley et al., 1993; Kapitsa et &l996 ; Siegert & Ridley,1998; Tabacco et al., 2002). To date, about 70 lakes have been discovered in all of Antarctica (Siegert et al.,1996); 21 of these are located in the Dome C-Vostok region.
    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: subglacial lakes ; RES systems ; East Antarctica ; 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 ; 02. Cryosphere::02.02. Glaciers::02.02.10. Instruments and techniques
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Conference paper
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 8
    facet.materialart.
    Unknown
    Reflecting Sub-Ice Surfaces Observed by Radio Echo Sounding System (2008)
    Terra Antartica Publication
    Details
    Publication Date: 2017-04-04
    Description: The reflection coefficient (R) at the interface of two media provides information on their electromagnetic nature. If the first medium is known, e.g. air (or ice, that in a broad interval of physical conditions maintains certain propagative characteristics nearly constant), the electromagnetic properties of the second medium can be determined. Hence, the ice/seawater, ice/water and ice/rock interfaces exhibit different reflection coefficients which can be detected by means of a RES system (Tabacco et al., 1999; Tabacco et al., 2000). The length of the radio wave does not allow the employment of sophisticated antennas, and so folded dipoles are arranged beneath the wings of the aircraft. As a consequence, the transmitted radio wave beam illuminates a relatively large area, and the power of the echo signal greatly depends on the shape of the reflecting surfaces. An electromagnetic analysis shows that, in certain conditions, the variations in amplitude detected by the system are mainly due to focusing or defocusing effects determined by the shape of the reflectors (Bianchi et al., 2001; Tabacco et al., 1999).
    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: Antarctica ; RES systems ; Radar equation ; 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::02.02.10. Instruments and techniques
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Conference paper
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 9
    facet.materialart.
    Unknown
    Un karst sous la glace de l'Antarctide ? (2008)
    Laboratoire EDYTEM
    Details
    Publication Date: 2017-04-04
    Description: A new bedrock map of the Dome C area based on all radar data collected during Italian Antarctic Expeditions in 1995, 1997, 1999 and 2001 is presented. The map can clearly distinguish the Dome C plateau, along with some valleys and ridges develop. 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 in its centre. The morphology of the major valley could be considered as a relict one which was not modified by the overlying ice cap. Two big ridges, characterized by hills, saddles and depressions, lie near the boundaries of the area. The hill and depression landscape may be the results of two different processes the weathering of granitic rocks, with the development of a "Wemi-oranges" and inselberg landscape, or the karstification of limestones, and development of a cone karst. The karstic hypothesis should be the more suitable, but it is impossible to exclude the granitic rock weathering. Both proposed genetic hypotheses call for a warm humide climate and a long period of stability in a continental environment. Consequently, the ice cap did not largely modified the landscape.
    Description: Published
    Description: 3.8. Geofisica per l'ambiente
    Description: N/A or not JCR
    Description: open
    Keywords: Antarctic ; geophysical methods ; polar karst ; ice cap ; under ice substratum ; 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: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 10
    facet.materialart.
    Unknown
    Radio echo sounding data analysis of the Shackleton Ice Shelf (2010)
    INGV
    Details
    Publication Date: 2017-04-04
    Description: In this study, our initial results are presented for the interpretation of the radio echo sounding data collected over the Shackleton Ice Shelf and adjacent ice sheet (East Antarctica) during the 2003/2004 Australian- Italian expedition. The Shackleton Ice Shelf is one of the larger ice shelves of the East Antarctic Ice Sheet. The radar survey provided data relating to ice thickness and bed morphology of the outlet glaciers, and thickness of their floating portions. The glacier grounding lines were determined by assessment of the basal echo characters. The information derived is compared with data from the BEDMAP database and from other sources.
    Description: Published
    Description: 79-87
    Description: 3.8. Geofisica per l'ambiente
    Description: JCR Journal
    Description: open
    Keywords: Ice ; Ice dynamics ; Geomorphology ; Instrument and techniques ; General or miscellaneous ; 02. Cryosphere::02.02. Glaciers::02.02.05. Ice dynamics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...