DOI: 10.1016/j.epsl.2018.08.003
Scopus记录号: 2-s2.0-85051492196
论文题名: Fragmentation and Plinian eruption of crystallizing basaltic magma
作者: Moitra P. ; Gonnermann H.M. ; Houghton B.F. ; Tiwary C.S.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 500 起始页码: 97
结束页码: 104
语种: 英语
英文关键词: basaltic Plinian eruption
; bubble growth and crystallization
; conduit model
; explosive magma fragmentation
; extensional rheometry
; oscillatory shear rheometry
Scopus关键词: Brittle fracture
; Deformation
; Explosives
; Glass transition
; Rheometers
; Suspensions (fluids)
; Viscoelasticity
; Viscosity
; Bubble growth
; Conduit model
; Extensional rheometry
; Magma fragmentation
; Oscillatory shear rheometry
; Plinian eruption
; Basalt
; basalt
; crystallization
; explosive volcanism
; magma
; modeling
; plinian eruption
; viscosity
英文摘要: Basalt is the most ubiquitous magma on Earth, erupting typically at intensities ranging from quiescently effusive to mildly explosive. The discovery of highly explosive Plinian eruptions of basaltic magma has therefore spurred debate about their cause. Silicic eruptions of similar style are a consequence of brittle fragmentation, as magma deformation becomes progressively more viscoelastic. Magma eventually crosses the glass transition and fragments due to a positive feedback between water exsolution, viscosity and decompression rate. In contrast to silicic eruptions, the viscosity of basaltic magmas is thought to be too low to reach conditions for brittle fragmentation. Pyroclasts from several basaltic Plinian eruptions, however, contain abundant micron-size crystals that can increase magma viscosity substantially. We therefore hypothesize that magma crystallization led to brittle fragmentation during these eruptions. Using combined oscillatory and extensional rheometry of concentrated particle-liquid suspensions that are dynamically similar to microcrystalline basaltic magma, we show that high volume fractions of particles and extension rates of about 1 s−1 or greater result in viscoelastic deformation and brittle fracture. We further show that for experimentally observed crystallization rate, basaltic magma can reach the empirical failure conditions when erupting at high discharge rates. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109690
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Department of Geology and Center for Geohazards Studies, University at Buffalo, Buffalo, NY, United States; Department of Earth, Environmental and Planetary Sciences, Rice UniversityTX, United States; Department of Geology and Geophysics, University of Hawai‘i at Manoa, Honolulu, United States; Department of Material Science and NanoEngineering, Rice University, Houston, TX, United States; Materials Science and Engineering, Indian Institute of Technology Gandhinagar, Gujarat, India
Recommended Citation:
Moitra P.,Gonnermann H.M.,Houghton B.F.,et al. Fragmentation and Plinian eruption of crystallizing basaltic magma[J]. Earth and Planetary Science Letters,2018-01-01,500