DOI: 10.1038/ngeo2042
论文题名: Supervolcano eruptions driven by melt buoyancy in large silicic magma chambers
作者: Malfait W.J. ; Seifert R. ; Petitgirard S. ; Perrillat J.-P. ; Mezouar M. ; Ota T. ; Nakamura E. ; Lerch P. ; Sanchez-Valle C.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2014
卷: 7, 期: 2 起始页码: 122
结束页码: 125
语种: 英语
Scopus关键词: buoyancy
; caldera
; dike
; environmental impact
; magma chamber
; melt
; overpressure
; volcanic eruption
; volcanology
英文摘要: Super-eruptions that dwarf all historical volcanic episodes in erupted volume and environmental impact are abundant in the geological record. Such eruptions of silica-rich magmas form large calderas. The mechanisms that trigger these super-eruptions are elusive because the processes occurring in conventional volcanic systems cannot simply be scaled up to the much larger magma chambers beneath supervolcanoes. Over-pressurization of the magma reservoir, caused by magma recharge, is a common trigger for smaller eruptions, but is insufficient to generate eruptions from large supervolcano magma chambers. Magma buoyancy can potentially create sufficient overpressure, but the efficiency of this trigger mechanism has not been tested. Here we use synchrotron measurements of X-ray absorption to determine the density of silica-rich magmas at pressures and temperatures of up to 3.6 GPa and 1,950 K, respectively. We combine our results with existing measurements of silica-rich magma density at ambient pressures to show that magma buoyancy can generate an overpressure on the roof of a large supervolcano magma chamber that exceeds the critical overpressure of 10-40 MPa required to induce dyke propagation, even when the magma is undersaturated in volatiles. We conclude that magma buoyancy alone is a viable mechanism to trigger a super-eruption, although magma recharge and mush rejuvenation, volatile saturation or tectonic stress may have been important during specific eruptions. © 2014 Macmillan Publishers Limited. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106462
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: Institute for Geochemistry and Petrology, ETH Zurich, Zurich 8092, Switzerland; European Synchrotron Radiation Facility, Grenoble 38000, France; Laboratoire de Géologie de Lyon, Université Claude Bernard Lyon 1 and Ecole Normal Supérieure de Lyon, CNRS UMR 5276, Villeurbanne 69622, France; Institute for Study of the Earth's Interior, Okayama University, Misasa, Tottori 682-0193, Japan; Paul Scherrer Institute, Villigen 5232, Switzerland
Recommended Citation:
Malfait W.J.,Seifert R.,Petitgirard S.,et al. Supervolcano eruptions driven by melt buoyancy in large silicic magma chambers[J]. Nature Geoscience,2014-01-01,7(2)