FLOWGO: a kinematic thermo-rheological model for lava flowing in a channel
FLOWGO: a kinematic thermo-rheological model for lava flowing in a channel
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DOI：
10.1007/s004450000120
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发表时间：
2001-05
影响因子：
3.5
通讯作者：
A. Harris;S. Rowland
中科院分区：
文献类型：
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作者：
A. Harris;S. Rowland
我们提出了一个运动学的，自适应的，数值模型来描述通道包含熔岩的向下流动的热和流变演化。当我们控制的熔岩沿着一条通道前进时，它冷却并结晶，一个越来越厚和广泛的表面地壳生长，它的热量收支和流变学发展。通过估计向下流动的热量和速度损失，我们的模型计算控制体积变得静止的点，给出熔岩在通道中流动的最大距离。模拟的渗出率，速度，宽度，表面地壳参数，热收支，冷却，温度，结晶度，粘度和屈服强度都比较好，在冒纳罗亚火山，克基拉韦厄火山和埃特纳火山喷发期间收集的现场数据。模型长度为25-27、2.5-5.7和0.59-0.83 km，而三种气流的测量长度分别为25-27、4和0.75 km。在近端流动部分，我们分别计算了1-10°C km-1、0.001-0.01体积分数km-1、103- 104 Pa s和10-3- 102 Pa的冷却、结晶、粘度和屈服强度。在流动前沿，冷却、结晶、粘度和屈服强度分别增加到>100°C km-1、0.1体积分数km-1、106- 107 Pa s和103- 104 Pa，所有这些联合收割机结合起来导致熔岩停止流动。我们的模型提出了一种方法（a）分析熔岩流的热流变关系;（B）确定重要因素，在确定多远的通道馈送流可以延伸;（c）评估熔岩流的危害;和（d）重建流态在史前，未观察到的，或远程流。
We present a kinematic, self-adaptive, numerical model to describe the down-flow thermal and rheological evolution of channel-contained lava. As our control volume of lava advances down a channel it cools and crystallizes, an increasingly thick and extensive surface crust grows, and its heat budget and rheology evolve. By estimating down-flow heat and velocity loss, our model calculates the point at which the control volume becomes stationary, giving the maximum distance lava flowing in the channel can extend. Modeled effusion rates, velocities, widths, surface crust parameters, heat budget, cooling, temperature, crystallinity, viscosity, and yield strength all compare well with field data collected during eruptions at Mauna Loa, Kĩlauea, and Etna. Modeled lengths of 25–27, 2.5–5.7, and 0.59–0.83 km compare with measured lengths of 25–27, 4, and 0.75 km for the three flows, respectively. Over proximal flow portions we calculate cooling, crystallization, viscosity, and yield strength of 1–10°C km–1, 0.001–0.01 volume fraction km–1, 103–104Pa s, and 10–3–102Pa, respectively. At the flow front, cooling, crystallization, viscosity, and yield strength increase to >100°C km–1, 0.1 volume fraction km–1, 106–107Pa s, and 103–104Pa, respectively, all of which combine to cause the lava to stop flowing. Our model presents a means of (a) analyzing lava flow thermo-rheological relationships; (b) identifying important factors in determining how far a channel-fed flow can extend; (c) assessing lava flow hazard; and (d) reconstructing flow regimes at prehistoric, unobserved, or remote flows.