eEarth www.electronic-earth.net 1815-381X 1815-3828 2 1 2007 10.5194/ee-2-1-2007 http://www.electronic-earth.net/2/1/2007/ http://www.electronic-earth.net/2/1/2007/ee-2-1-2007.html http://www.electronic-earth.net/2/1/2007/ee-2-1-2007.pdf 1 5 2007-01-04 Fall-experiments on Merapi basaltic andesite and constraints on the generation of pyroclastic surges L. M. Schwarzkopf lothar_schwarzkopf@yahoo.de O. Spieler B. Scheu D. B. Dingwell Earth & Environmental Sciences, Ludwig-Maximilians-Universität München, Theresienstr. 41/III, 80333 München, Germany GeoDocCon, Unterpferdt 8, 95176 Konradsreuth, Germany We have performed fall-experiments with basaltic andesite rock samples from Merapi volcano, using an apparatus designed to analyze samples heated up to 850°C. Relative pressure changes during impact and fragmentation of the samples were measured by a pressure transducer. From 200°C, dynamic pressure waves were formed on impact and fragmentation. 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