Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 88 for “"subglacial"”.
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Volatiles in Icelandic subglacial rhyolite
Magmatic volatiles from subglacial edifices offer useful insights into palaeo-ice thicknesses and during subaerial eruptions are a strong influence on eruptive behaviour. However, pre-eruptive volatile concentrations and degassing paths are lacking from subglacially erupted edifices and thus the …
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Subglacial rhyolite volcanism at Torfajökull, Iceland
Subglacial rhyolite eruptions at Torfajökull, Iceland have produced a variety of volcanic edifices during the last glacial period (115-11 ka). These range from small-volume (<0.1 km<sup>3</sup>) volcanoes, such as Bláhnúkur and Dalakvíslfell, to larger volume (~1 km<sup>3</sup>) flat-topped tuyas …
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Modelling the propagation of subglacial floods
Subglacial flooding, in which large volumes of water are suddenly released beneath a glacier, is a process which has the potential to significantly modify the dynamics of the overlying ice. The routing of the water beneath the glacier and the extent of its incorporation into existing drainage …
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Modeling Subglacial Hydrology in the Himalayas
… mass balance are all likely strongly affected by subglacial hydrology. Unfortunately, little is known about Himalayan glaciers due to their remoteness and the danger of doing field work there. Recent advances in subglacial hydrological modeling may allow us to shed more light on subglacial …
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Toward system level autonomy for planetary subglacial access missions
L'abstract è presente nell'allegato / the abstract is in the attachment
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The drumlin problem : streamlined subglacial bedforms in southern Sweden
This thesis investigates stream-lined subglacial bedforms (often referred to as drumlins) in southern Sweden. The broad aim of this is to contribute to the solution of the ‘drumlin problem’. The term drumlin has come to be applied to a wide range of features whose internal architecture (core) and …
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Airborne geophysical investigations of subglacial structure of West Antarctica
… data are discussed and interpretations of subglacial geology made. Discussion concentrates on defining boundaries between major structural units in West Antarctica and the boundary between East and West Antarctica. The tectonic evolution and position of West Antarctica in Gondwanaland is …
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Evolving subglacial water systems in East Antarctica from airborne radar sounding
… interest to a wide range of disciplines. Stable subglacial lakes and their connecting channels remain perennially liquid three kilometers below some of the coldest places on Earth. The presence of subglacial water impacts flow of the overlying ice and provides clues to the geologic properties of …
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Modelling the subglacial drainage system of Petermann Glacier, north-west Greenland
… temperatures can raise the pressure in the subglacial drainage system as meltwater input increases and the system fails to efficiently evacuate it. Some studies suggest that increased temperatures and meltwater input will slow glaciers down by causing earlier channelization, allowing stable …
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Meteoric 10Be as a Tracer for Subglacial Chemical Weathering in East Antarctica
Subglacial chemical processes in Antarctica are potentially significant contributors to global geochemical cycles, but current understanding of their scale and nature is limited. A sequential chemical extraction procedure was developed and tested to investigate the utility of meteoric 10Be as a …
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The influence of subglacial hydrology on the flow of West Antarctic ice streams
Subglacial hydrology is known to influence the flow of ice. However, difficulty in accessing the base of large ice sheets has made determining the interaction between ice streams, basal sediment and water difficult to discern. The aim of this thesis is to determine the influence of subglacial …
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Hydraulic properties of subglacial sediment determined from the mechanical response of water-filled boreholes
… of water-filled boreholes drives water into the subglacial bed and the associated pressure effects give information about subglacial hydraulic properties. A numerical model describing the mechanical response of an unconnected borehole and the bed beneath it to this freezing forcing was developed, …
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Constraining the pathways and fluxes of subglacial meltwater beneath the palaeo-Antarctic Ice Sheet
… continental shelf imply that there was an active subglacial hydrological system beneath the palaeo Antarctic Ice Sheet. The dimensions of the channelised features is inconsistent with the minimal quantities of meltwater produced under the Antarctic Ice Sheet at present; consequently, their …
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Inferring subglacial hydrology from investigations of supraglacial lake drainages and meltwater plumes at Store Glacier, West Greenland
… glaciers. Tidewater glaciers each have unique subglacial drainage systems and discharge meltwater into adjacent fjords differently. However, studies of the subglacial hydrology of individual tidewater glaciers have been limited, largely due to the difficulty in obtaining direct measurements. …
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Cryogenic carbon cycling at an Icelandic glacier
… forms, across supraglacial, englacial and subglacial realms. It is often difficult to detach cryospheric carbon cycling from hydrology, with the transfer of carbon between glacial inventories relying upon meltwater flows. Classical glacial hydrology consists of distributed drainage …
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Characterization of the basal hydraulic system of a surge-type glacier : Trapridge Glacier, 1989-92
Subglacial hydrology is a critical issue in understanding glacier and ice-sheet dynamics. This is especially true for surge-type glaciers, which are distinguished by their regular, quasi-periodic alternation between slow and fast flow regimes (Meier and Post, 1969); the fast flow during a surge is …
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Connect Store: A fully coupled 3D model of ice flow, calving, subglacial hydrology and ice-ocean interactions applied to Store Glacier, Greenland
… the coupled dynamics of the ice-calving-subglacial-hydrology-plume system at Store Glacier, a large, fast-flowing tidewater outlet glacier on the west coast of Greenland. Understanding these large outlet glaciers is critical to being able to accurately predict the future evolution of the …
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