Crumbling of dacite dome lava and generation of pyroclastic flows at Unzen volcano
Article Abstract:
Lava domes formed in the 1991 eruption of the Unzen volcano in Japan were observed to generate both Merapi and Pelean type pyroclastic flows. Most of these glowing avalanches were of the Merapi type which result from blocks falling as a dome collapses, however some of the Pelean type were observed which result when the side of a dome explodes. Different lavas differ in self-explosivity which may result from differing gas pore pressures relative to tensile strength. These differences probably result from variable degassing of the magma and underlie the formation of both Merapi and Pelean type flows.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1992
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Mount Unzen rumbles on
Article Abstract:
Comparison of Japan's Mount Unzen volcano with Mount St. Helens and analysis of Unzen's dome-building indicate that Unzen has a high probability of repeating its Jun 1991 eruption within the next several years. Mount Unzen's lava dome grew more in the 10 months following the last eruption than Mount St. Helens's did in six years, suggesting that Unzen retains its capacity for violent eruption. Moreover, the composition of Unzen's lava resembles that of active volcanoes. All in all, the Japanese authorities would be wise to continue enforcing the present evacuation zones around the volcano.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1992
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Exploding volcanic myths
Article Abstract:
New modeling experiments help study volcanic eruption, revealing potentially dangerous processes that are normally unanticipated. Eruptive phenomena is modelled based on the triggering of explosive through pressure release. These experiments will help predict dangers of future eruptions, thereby reducing risks of volcanism.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1995
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