3 research outputs found
GeodÀtische Erdsystemforschung mittels Satellitenfernerkundung
Beitrag zur geodĂ€tischen Erdsystemforschung mittels Satellitenfernerkundung anlĂ€Ălich anlĂ€Ălich einer Festschrift zum 65. Geburtstag von Prof. Reinhard Dietrich
Zum VerstĂ€ndnis des eisigen SĂŒdens - 20 Jahre Forschung in GeodĂ€sie, Geodynamik und Glaziologie 1992-2012: Festschrift zum 65. Geburtstag von Prof. Reinhard Dietrich
Am 24. September 2014 hat Professor Reinhard Dietrich sein 65. Lebensjahr vollendet. ZurĂŒckblicken kann er auf eine ĂŒberaus reiche Lehr- und ForschungstĂ€tigkeit. Fast genau 20 Jahre war er Professor fĂŒr Theoretische und Physikalische GeodĂ€sie an der TU Dresden, bevor er zum 1. Oktober 2012 in den Ruhestand eintrat. Sein Geburtstag ist uns, die wĂ€hrend dieser Zeit mit ihm zusammen forschen und lehren durften, Anlass, eine Festschrift zu verfassen und dem Jubilar sowie allen Kollegen und Freunden an die Hand zu geben. Eine WĂŒrdigung seiner Lehr- und ForschungstĂ€tigkeit können Sie auf den folgenden Seiten nachlesen.:Vorwort 7
âGrenzen setzt uns nur die eigene Phantasieâ Reinhard Dietrich â Versuch einer WĂŒrdigung 9
GNSS â ein Werkzeug fĂŒr globale und regionale geophysikalische Forschung 17
Zum Stand des Höhenbezugsrahmens in Deutschland 37
GeodÀtische Erdsystemforschung mittels Satellitenfernerkundung 53
Wasser und Eis â Satellitendaten zur Bilanzierung von Massentransporten 69
GeodÀtische Bestimmung glaziologischer Parameter in Grönland 83
GeodÀtische Arbeiten im Gebiet des subglazialen Lake Vostok 93
Feuerland: Symptome einer aktiven Plattengrenze 107
Anhang A â Verzeichnis der Promotionen 117
Anhang B â Publikationsliste R. Dietrich 11
Ice dynamics and mass balance in the grounding zone of outlet glaciers in the Transantarctic Mountains
The Antarctic grounding zone has a disproportionately large effect on glacier dynamics and ice sheet stability relative to its size but remains poorly characterised across much of the continent. Accurate ice velocity and thickness information is needed in the grounding zone to determine glacier outflow and establish to what extent changing ocean and atmospheric conditions are affecting the mass balance of individual glacier catchments.
This thesis describes new satellite remote sensing techniques for measuring ice velocity and ice thickness, validated using ground measurements collected on the Beardmore, Skelton and Darwin Glaciers and applied to other Transantarctic Mountain
outlet glaciers to determine ice discharge. Outlet glaciers in the Transantarctic Mountains provide an important link between the East and West Antarctic Ice Sheets but remain inadequately studied. While long-term velocities in this region
are shown here to be stable, instantaneous velocities are sensitive to stresses induced by ocean tides, with fluctuations of up to 50% of the mean observed in GPS measurements. The potential error induced in averaged satellite velocity measurements due to these effects is shown to be resolvable above background noise in the grounding zone but to decrease rapidly upstream. Using a new inverse finite-element modelling
approach based on regularization of the elastic-plate bending equations, tidal flexure information from differential InSAR is used to calculate ice stiffness and infer thickness in the grounding zone. This technique is shown to be successful at reproducing the thickness distribution for the Beardmore Glacier, eliminating current issues in the calculation of thickness from freeboard close to the grounding line where ice is not in hydrostatic equilibrium. Modelled thickness agrees to within 10% of ground penetrating radar measurements. Calibrated freeboard measurements and tide-free velocities in the grounding zones of glaciers in the western Ross Sea are used to calculate grounding zone basal melt rates, with values between 1.4 and 11.8 m/aâ»Âč in this region. While strongly dependent on grounding line ice thickness and velocity, melt rates show no latitudinal trend between glaciers, although detailed error analysis highlights the need for much improved estimates of firn density distribution in regions of variable accumulation such as the Transantarctic Mountains