Thermal and Rheological Controls on the Emplacement of Basaltic Lava Flows

玄武岩熔岩流就位的热流变控制[au: 0207919]这是一个更新的提案，直接遵循了之前的主题和方法。最近对夏威夷活跃的pahoehoe和‘ a ’ a流动的研究，包括pi的研究，表明流动形态和就位之间的明确联系涉及冷却、结晶和流动推进的相对速度。关键是熔岩从喷口向流锋运输的条件。流动表面形态的现场观察导致了晶体-液体悬浮液屈服强度发展的流变学研究。利用聚乙二醇蜡进行的新实验表明，均匀通道化流动中的凝固可以用单一的无量纲参数和通道长径比来描述。不均匀性，如沟道分叉、收缩和弯曲也可能稳定或破坏表面地壳。前一个奖项的结果说明了这些方法的成功。目前的合同将使用高分辨率卫星遥感来绘制玄武岩流动图，完成额外的模拟实验，以更好地定义重要的材料参数和流动控制，并将模型预测与详细的流动现场观测进行比较。这个更新奖继续支持Cashman（俄勒冈大学）、Kauahikaua（美国地质勘探局、夏威夷火山观测站）和Griffiths & Kerr（澳大利亚国立大学）之间的合作。研究团队汇集了夏威夷熔岩流现场测绘和解释的专业知识，以及固化流流体力学分析的专业知识。

Thermal and Rheological Controls on the Emplacement of Basaltic Lava FlowsEAR-0207919PIs: Cashman & KauahikauaThis is a renewal proposal that follows directly in theme and approach to the previous award. Recent studies of active pahoehoe and `a`a flows in Hawai`i, including those by the PIs, have shown that the explicit link between flow morphology and emplacement involves the relative rates of cooling, crystallization, and flow advance. Critical are conditions of lava transport from the vent to the flow front. Field observations of flow surface morphologies have led to rheological studies on yield strength development in crystal-liquid suspensions. Novel experiments using PEG wax suggest that solidification in uniform channelized flows may be described by a single dimensionless parameter and channel aspect ratio. Non-uniformities such as channel divergences, constrictions, and sinuosity also may stabilize or disrupt surface crust. Results from the previous award illustrate the success of these approaches. The current award will use high resolution satellite remote sensing to map basaltic flows, complete additional analog experiments to better define important material parameters and flow controls, and compare model predictions with detailed field observations of flows. This renewal award continues support for the collaboration between Cashman (Univ. of Oregon), Kauahikaua (U.S.G.S., Hawaiian Volcano Observatory), and Griffiths & Kerr (Australian National University). The research team brings together expertise on the field mapping and interpretation of Hawaiian lava flows and expertise on fluid mechanical analysis of solidifying flows.