Collaborative Proposal: Evolution of Lava Channel Networks: Implications for Lava Flow Hazards and Mitigation

熔岩河是夏威夷等地火山活动的标志性表现。虽然很少致命，但熔岩流通常会对财产构成威胁，这种风险可能足以让政府当局决定建造屏障来转移这些流动（例如，1983年、1991年和2001年在意大利埃特纳火山，以及1960年在夏威夷）。然而，屏障的建造与其说是一门科学，不如说是一门艺术，熔岩流与地形屏障之间的相互作用还没有得到很好的研究。障碍物也可能存在于熔岩流过的地形中，要么以预先存在的地形的形式存在，要么以熔岩流就位和固化时形成的地形的形式存在。遇到障碍物的熔岩流要么在周围分裂，形成单独的（较小和较慢的）熔岩流裂片，要么可能被大型障碍物（如悬崖）集中成大型（快速移动的）熔岩流。这些行为必须被理解，以模拟活跃流的发展，这对于评估和减轻频繁熔岩流活动地区（如夏威夷、意大利和冰岛）的火山危害至关重要。本研究将通过以下方法来研究复杂熔岩流的发展和稳定性：(1)分析最近夏威夷熔岩流中保存的通道网络；(2)进行实验室实验，以确定障碍物对粘性流体（模拟流体和熔融玄武岩）遇到地形障碍物时下坡运动的影响；(3)从实验中开发的模型，并将其应用于活动熔岩流。此外，近期夏威夷熔岩流的通道网络将在高分辨率数字高程模型（dem）和航空照片上进行识别，分析网络模式，并在现场进行调查。实地研究将包括通过摄影测量法记录熔岩-地形相互作用结构，并建立特定通道特征的3D模型。新的数字高程模型将使用基于TanDEM-X卫星的雷达成像和摄影测量技术为目标区域创建。俄勒冈大学、布里斯托尔大学、拉蒙特-多尔蒂地球观测站和美国地质调查局夏威夷火山观测站的科学家们将通过合作，使这种多管齐下的方法成为可能。

Rivers of molten lava are iconic manifestations of volcanic activity in places like Hawaii. Although rarely fatal, lava flows commonly pose risks to property, risks that may be sufficient that government authorities decide to build barriers to divert those flows (for example, at Mt. Etna, Italy, in 1983, 1991 and 2001, and in Hawaii in 1960). However, barrier construction is more an art than a science, and the interaction between lava flows and topographic barriers has not been well researched. Barriers may also exist in the landscape over which lava travels, either in the form of pre-existing topography or in topography that is constructed as lava flows are emplaced and solidify. Lava flows that encounter barriers will either split around them to form separate (smaller and slower) lava flow lobes, or may be focused by large obstacles (such as cliffs) into large (and fast-moving) flows. These behaviors must be understood to model the advance of active flows, which is essential for assessing and mitigating volcanic hazards in regions of frequent lava flow activity (such as Hawaii, Italy and Iceland). This research will investigate the development and stability of complex lava flows using (1) analysis of channel networks preserved in recent Hawaiian lava flows, (2) laboratory experiments performed to determine the effect of obstacles on the downslope movement of viscous fluids (both analogue fluids and molten basalt) when they encounter topographic obstacles, and (3) models developed from the experiments and applied to active lava flows. Additionally, channel networks in recent Hawaiian lava flows will be identified on high resolution digital elevation models (DEMs) and aerial photos, analyzed for network patterns, and investigated in the field. Field studies will include documentation of lava-topography interaction structures via photogrammetry and construction of 3D models of specific channel features. New digital elevation models will be created for target areas using both TanDEM-X satellite-based radar imaging and by photogrammetry. This multi-pronged approach will be made possible by collaborations among scientists at the University of Oregon, University of Bristol, Lamont-Doherty Earth Observatory, and the USGS Hawaiian Volcano Observatory.