DOI: 10.1016/j.epsl.2019.115903
论文题名: Periodic outgassing as a result of unsteady convection in Ray lava lake, Mount Erebus, Antarctica
作者: Birnbaum J. ; Keller T. ; Suckale J. ; Lev E.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 530 语种: 英语
中文关键词: bidirectional flow
; conduit
; convection
; Erebus volcano
; lava lake
; multi-phase model
英文关键词: Dynamics
; Heat convection
; Heat flux
; Volcanoes
; Bi-directional flows
; conduit
; Multiphase model
; Periodic behavior
; Periodic process
; Steady-state behaviors
; Surface observation
; Volcanic conduit
; Lakes
; computer simulation
; crater lake
; degassing
; diapir
; flow field
; lava
; multiphase flow
; numerical model
; periodicity
; volcanic eruption
; volcanology
; Antarctica
; East Antarctica
; Mount Erebus
; Ross Island
英文摘要: Persistently active lava lakes show continuous outgassing and open convection over years to decades. Ray Lake, the lava lake at Mount Erebus, Ross Island, Antarctica, maintains long-term, near steady-state behavior in temperature, heat flux, gas flux, lake level, and composition. This activity is superposed by periodic small pulses of gas and hot magma every 5-18 min and disrupted by sporadic Strombolian eruptions. The periodic pulses have been attributed to a variety of potential processes including unstable bidirectional flow in the conduit feeding the lake. In contrast to hypotheses invoking a conduit source for the observed periodicity, we test the hypothesis that the behavior could be the result of dynamics within the lake itself, independent of periodic influx from the conduit. We perform numerical simulations of convection in Ray Lake driven by both constant and periodic inflow of gas-rich magma from the conduit to identify whether the two cases have different observational signatures at the surface. Our simulations show dripping diapirs or pulsing plumes leading to observable surface behavior with periodicities in the range of 5-20 min. We conclude that a convective speed faster than the inflow speed can result in periodic behavior without requiring periodicity in conduit dynamics. This finding suggests that the surface behavior of lava lakes might be less indicative of volcanic conduit processes in persistently outgassing volcanoes than previously thought, and that dynamics within the lava lake itself may modify or overprint patterns emerging from the conduit. Beyond its importance for Erebus, this result highlights the need to understand periodic processes emerging at all levels of the volcanic plumbing system in order to interpret surface observations. © 2019 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164870
Appears in Collections: 气候变化与战略
There are no files associated with this item.
作者单位: Lamont-Doherty Earth Observatory, Columbia UniversityNY, United States; Stanford UniversityCA, United States
Recommended Citation:
Birnbaum J.,Keller T.,Suckale J.,et al. Periodic outgassing as a result of unsteady convection in Ray lava lake, Mount Erebus, Antarctica[J]. Earth and Planetary Science Letters,2020-01-01,530