DOI: 10.1016/j.epsl.2018.04.044
Scopus记录号: 2-s2.0-85046633768
论文题名: Magma ascent and lava flow emplacement rates during the 2011 Axial Seamount eruption based on CO2 degassing
作者: Jones M.R. ; Soule S.A. ; Gonnermann H.M. ; Le Roux V. ; Clague D.A.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 494 起始页码: 32
结束页码: 41
语种: 英语
英文关键词: Axial Seamount
; CO2 in MORB
; eruption mechanisms
; lava flow emplacement
; magma ascent rates
; mid-oceanic ridge basalts
; submarine volcanism
Scopus关键词: Basalt
; Carbon dioxide
; Degassing
; Dissolution
; Submarines
; Tectonics
; Axial Seamount
; CO2 in MORB
; Eruption mechanisms
; Lava flow emplacements
; Magma ascents
; Mid-oceanic-ridge basalts
; Submarine volcanism
; Submarine geology
; carbon monoxide
; degassing
; emplacement
; lava flow
; magma
; mid-ocean ridge basalt
; submarine volcano
; volcanic eruption
; volcanism
; Axial Volcano
; Juan de Fuca Ridge
; Pacific Ocean
英文摘要: Quantitative metrics for eruption rates at mid-ocean ridges (MORs) would improve our understanding of the structure and formation of the uppermost oceanic crust and would provide a means to link volcanic processes with the conditions of the underlying magmatic system. However, these metrics remain elusive because no MOR eruptions have been directly observed. The possibility of disequilibrium degassing in mid-ocean ridge basalts (MORB), due to high eruptive depressurization rates, makes the analysis of volatile concentrations in MORB glass a promising method for evaluating eruption rates. In this study, we estimate magma ascent and lava flow emplacement rates during the 2011 eruption of Axial Seamount based on numerical modeling of diffusion-controlled bubble growth and new measurements of dissolved volatiles, vesicularity, and vesicle size distributions in erupted basalts. This dataset provides a unique view of the variability in magma ascent (∼0.02–1.2 m/s) and lava flow rates (∼0.1–0.7 m/s) during a submarine MOR eruption based on 50 samples collected from a >10 km long fissure system and three individual lava flow lobes. Samples from the 2011 eruption display an unprecedented range in dissolved CO2 concentrations, nearly spanning the full range observed on the global MOR system. The variable vesicularity and dissolved CO2 concentrations in these samples can be explained by differences in the extent of degassing, dictated by flow lengths and velocities during both vertical ascent and horizontal flow along the seafloor. Our results document, for the first time, the variability in magma ascent rates during a submarine eruption (∼0.02–1.2 m/s), which spans the global range previously proposed based on CO2 degassing. The slowest ascent rates are associated with hummocky flows while faster ascent rates produce channelized sheet flows. This study corroborates degassing-based models for eruption rates using comparisons with independent methods and documents the relationship between eruption dynamics, magma ascent rates, and the morphology of eruptive products. Globally, this approach allows interrogation of the processes that govern mid-ocean ridge eruptions and influence the formation of the oceanic crust. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109841
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: Massachusetts Institute of Technology/Woods Hole Oceanographic Institution Joint Program in Oceanography, Woods Hole, MA 02543, United States; Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States; Department of Earth, Environmental and Planetary Sciences, Rice University, Houston, TX 77005, United States; Monterey Bay Aquarium Research Institute, Moss Landing, CA 95039, United States
Recommended Citation:
Jones M.R.,Soule S.A.,Gonnermann H.M.,et al. Magma ascent and lava flow emplacement rates during the 2011 Axial Seamount eruption based on CO2 degassing[J]. Earth and Planetary Science Letters,2018-01-01,494