Collaborative Research: Quantifying the Emplacement of Channeled Flow Using Experimental, Analytical and Numerical Analyses

虽然槽状熔岩流在整个太阳系都很常见，但是槽状形态、喷发和就位参数以及熔岩性质之间的关系还没有得到很好的理解。我们之前的研究结果，将分析模型与精心控制的实验室模拟相结合，提出了许多可用数据无法解决的问题。我们目前的建议是通过收集来自额外实验室模拟的数据来解决这些限制，特别是为了分离潜在斜坡和斜坡断裂对通道发育的影响，流变学的影响，以及温度依赖性粘度对通道形态的影响。这将通过在实验室中使用PEG（一种具有温度依赖粘度的牛顿流体）、高岭土带电PEG（一种具有温度依赖粘度的宾厄姆流体）和高岭土浆料（一种等温宾厄姆流体）在不同的下垫坡（1度-50度）上产生通道流动来实现。通道实验室流动中的速度分布将使用中性浮力彩色珠子作为示踪剂注入流动中仔细测量。Sakimoto博士开发的计算流体动力学（CFD）流动模拟将被修改，以处理实验室流动中发现的条件。将进行初步的CFD模拟，以了解温度分布不均匀、PEG和罐底向实验室环境的热损失以及PEG向周围蔗糖溶液扩散等影响在实验室流动中的重要性。由Gregg博士进行的模拟流动的形态参数将被测量，用于验证和完善CFD模拟结果。反过来，CFD模拟将用于充分表征和理解在实验室中主导流体放置和冷却的物理过程。这些结果将用天然的玄武岩熔岩流进行测试，比如1984年夏威夷莫纳罗亚火山的喷发，以及目前夏威夷基拉韦厄火山普乌奥奥火山喷发时产生的较小的pahohoe通道。

GreggEAR-0001295Although channeled lava flows are common throughout the solar system, relations between channel morphology, eruption and emplacement parameters, and lava properties are not well understood. Results from our previous study, combining analytical models with carefully controlled laboratory simulations raised many questions that could not be addressed withavailable data. Our current proposal addresses these limitations by collecting data from additional laboratory simulations, specifically to isolate the effects of underlying slope and slope breaks on channel development, the effects of rheology, and the effects of temperature-dependent viscosities on channel morphology. This will be accomplished by using PEG (a Newtonian fluid with a temperature-dependent viscosity), kaolin-charged PEG (a Bingham fluid with a temperature-dependent viscosity) and kaolin slurries (an isothermal Bingham fluid) to generate channeled flows on different underlying slopes (1degree-50 degrees) in the laboratory. Velocity distributions within channeled laboratory flows will be carefully measured using neutrally buoyant colored beads injected into the flow as tracers. Computational fluid dynamics (CFD) flow simulations developed by Dr. Sakimoto will be modified to treat the conditions found in laboratory flows. Preliminary CFD simulations will be run to understand the significance in laboratory flows of such effects as non-homogenous temperature distributions, heat loss from the PEG and tankbottom to the laboratory environment, and diffusion of PEG into the surrounding sucrose solution. Morphologic parameters from the simulated flows conducted by Dr. Gregg will be measured used to validate and refine CFD simulation results. The CFD simulations, in turn, will be used to fully characterize and understand the physical processes that dominate flowemplacement and cooling in the laboratory. These results will be tested against natural basaltic lava flows, such as the 1984 Mauna Loa, Hawaii eruption and smaller pahoehoe channels produced during the current eruption of Pu'u O'o at Kilauea volcano, Hawaii.