000K utf8 1100 $c2006 1500 eng 2050 urn:nbn:de:gbv:8-diss-17946 3000 Lube, Gert 4000 The flow and depositional mechanisms of granular matter : experimental and field studies with implications for pyroclastic flows$hChristian-Albrechts-Universität zu Kiel [Lube, Gert] 4030 Kiel$nChristian-Albrechts-Universität zu Kiel 4209 This Doctorial Thesis investigates the fundamental problem of flow and deposition processes of unsteady, inertial flows of granular media and elucidates its implications for the behaviour of pyroclastic flows formed in explosive volcanic eruptions. A three-fold approach is followed including laboratory experiments, their theoretical analysis, and field work on the pristine pyroclastic flow deposits of the 1975 eruption of Mt. Ngauruhoe (New Zealand). The experiments are based upon the physical problem of the sudden collapse of vertical columns of granular media onto a base and their subsequent spreading behaviour. Through investigations of the pyroclastic flow deposits of the 1975 eruption of Mt. Ngauruhoe, first complete data sets of the internal structure and grain-size distribution and the morphology of the upper free surface of small-volume pyroclastic flow deposits as a function of travel distance, underlying slope and topographic confinement are presented. This detailed data set is interpreted using the experimental findings on the propagation of an internal interface, and a qualitative time- and space-dependent model on transport, segregation and deposition is developed for pyroclastic flows. 4950 https://nbn-resolving.org/urn:nbn:de:gbv:8-diss-17946$xR$3Volltext$534 4961 https://macau.uni-kiel.de/receive/diss_mods_00001794 5051 550 5550 granular column collapse 5550 granular flow 5550 Ngauruhoe 5550 pyroclastic flow 5550 Pyroklastischer Strom 5550 transport and deposition mechanisms