Standing waves in high speed lava channels: A tool for constraining lava dynamics and eruptive parameters
Standing waves in high speed lava channels: A tool for constraining lava dynamics and eruptive parameters
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DOI：
10.1016/j.jvolgeores.2020.106944
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发表时间：
2020-09-01
影响因子：
2.9
通讯作者：
Anzieta, J.
中科院分区：
文献类型：
--
作者：
Le Moigne, Y.;Zurek, J. M.;Anzieta, J.
对熔岩流的流变性的估计对于了解它们的就位和危险评估是必不可少的。尽管在水力学中是一个众所周知的现象，但对熔岩通道中驻波的形成和存在却知之甚少。驻波通常位于喷口附近，经常被描述为高速沟道化熔岩流。它们被解释为指示超临界条件下的流动的水力跳跃。因此，识别驻波提供了将明渠水力理论应用于超临界流动的机会，以便确定重要的喷发参数，如流量和表观粘度。我们利用驻波的长度和幅度从观测数据和视频分析中重建流动动力学。这些驻波的几何形状使我们能够提取沟道化熔岩的物理性质(速度、流量、表观粘度)，以估计河道深度并约束流态。随着技术的快速进步，科学家可以部署设备，以实现对这些现象的低成本实时监测，并限制喷发排放率和表观粘度，这是评估和减轻火山灾害的关键参数。(C)2020爱思唯尔B.V.保留所有权利。
Estimates of the rheological properties of lava flows are essential for understanding their emplacement and for hazard assessment. Despite being a well-known phenomenon in water hydraulics, the formation and presence of standing waves in lava channels is poorly understood. Standing waves, generally located near the vent area, have been frequently described at high speed channelized lava flows. They are interpreted as hydraulic jumps indicating a flow under supercritical conditions. Identifying standing waves therefore offers an opportunity to apply open channel hydraulic theory for supercritical flows in order to determine important eruption parameters such as discharge rate and apparent viscosity. We use the length and amplitude of standing waves to reconstruct flow dynamics from both observational data and video analysis. The geometry of these standing waves allows us to extract the physical properties of the channelized lava (velocity, discharge rate, apparent viscosity), to estimate the channel depth and constrain the flow regime. With the rapid advances in technology scientists can deploy equipment to enable low-cost real time monitoring of these phenomena and constrain eruption discharge rate and apparent viscosity, key parameters for volcanic hazard assessment and mitigation. (C) 2020 Elsevier B.V. All rights reserved.