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Instituto de Investigação
em Vulcanologia e Avaliação de Riscos
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Comunicações orais ► em encontros internacionais


Referência Bibliográfica

SCHEU, B., KUEPPERS, U., SPIELER, O., DINGWELL, D. (2007) - Experimental volcanology on eruptive products of Unzen Volcano: 1990 - 1995 eruption. Cities on Volcanoes 5 conference, Shimabara, Japão, 19 - 23 Novembro (Comunicação Oral).


Protracted dome-building eruptions may be profitably investigated by a wide range of techniques, including laboratory-based experiments. Here we present a comprehensive review of experimental work on the products of the 1990-1995 eruption of Unzen Volcano, Japan, and their application to the eruption dynamics of Unzen: Rapid decompression experiments focused on several aspects of the degassing (permeability) and the fragmentation behavior (threshold, speed, and efficiency).


Those investigations have been flanked by analyses of flexural strength, fracture toughness, seismic velocities, to provide new insights into processes as for instance dome failure. Density distribution studies of the pyroclastic flow deposits of the 1990-1995 eruption allow us to apply the results of experimental investigations on Unzen dacite to the interpretation of the last its eruption.


Thus implications for an overall view of a volcanic system are provided in this study. We evaluated a dependence of elastic wave velocities on temperature changes; this accounts for the host rock as well as the conduit margin and bears vital constraints for the interpretation and modeling of volcano seismic data. The results of the fragmentation experiments are applicable for dome rocks, the vesicular interior of a conduit, and rocks from the conduit margin and contain important implications for the modeling of volcanic processes.


Combining the results of the performed experiments is likely to contribute effectively to a refined understanding of pre- and syn-eruptive processes. This may allow an improved analysis of precursor phenomena in volcanic areas and consequently provide important constraints to the hazard and risk management.