Collection of a High-Resolution Spatial and Ground-Based Dataset From the 2010 Explosive Events at Merapi Volcano, Java, Indonesia

该项目由岩石和地球化学计划（地球科学理事会地球科学部）与国际科学与工程办公室合作支持。默拉皮火山位于人口稠密的中爪哇，是印度尼西亚最活跃和最危险的火山之一。经过四年的沉寂，2010年10月26日开始爆发，其特点是伴随着火山碎屑密度流（PDCs）向火山的西部和南部地区传播。10月27日的报告指出，约有35人死亡，若干人受伤。在接下来的几天里，爆炸活动不断增加，直到2010年11月4日和5日，一系列大爆炸将各种PDCs发送到距离山顶15公里的地方，造成300多人死亡。根据默拉皮火山观测站火山学和地质灾害减灾中心的数据，这是该火山自1872年以来最大的一次喷发，目前的火山爆发指数估计在3到4之间。这些危险的爆炸事件为收集PDC沉积的来源、范围、横向变化和对人口稠密地区的影响的独特详细数据提供了难得的机会。申请的紧迫性源于与这些事件相关的原始沉积物的短暂性：这些沉积物很快就会被印度尼西亚当前的雨季冲走，而且很难有机会从这种危险的火山流中收集关键数据。RAPID的主要目标是与一个国际团队一起收集足够的数据，以便：1)记录2010年默拉皮火山爆发危机期间产生的不同PDCs的来源、持续时间和跳动距离；2)利用不同地基技术测量2010年不同PDC层的范围、分布、形态、岩性和厚度的变化；3)获取并计算喷发前、期间和之后拍摄的空间图像汇编。地形对流动动力学的影响将在流动就位后（一旦这些区域被认为是安全的），通过实时GPS /激光测距仪对相关沉积物表面进行调查，在现场进行检查。这样一个数据集的收集将用于生成喷发前后的数值地形，以测试对地球物理质量流模型（GMFM）输出的各种质量的自然地形数字表示的敏感性。将基于TanDEM mission - x计算高分辨率基准DEM数据集（大约3米空间分辨率，1-2米垂直精度）。应用TerraSAR数据生成精确的数值地形和/或捕获与PDC沉积就位相关的短期快速地形变化，对于更好地了解此类危险火山流的动力学具有巨大的潜在好处。以前的作者已经表明，在计算程序中选择DEM对于重建各种流动的不同路径、速度和范围，以及正确估计与未来火山活动相关的危险区域和水平的重要性。在该项目中获得的数据也将使用免费的GMFMs集成到数值模拟中，并允许这些模型的有效性进行测试，更好地量化最佳拟合输入参数。这一方法将为确定默拉皮受PDCs威胁的关键地区的危险区提供一个基础，这可以直接纳入这个高风险火山目前的减灾计划。因此，这里提出的工作将对直接（在世界上一些最活跃的火山上的观测站）或通过遥感技术参与评估火山危害的所有小组都有直接的好处。该项目将为Sylvain Carbonnier （USF博士后研究员，2012年8月结束）提供直接支持，并为Jose Armando Saballos （USF博士生，研究尼加拉瓜康塞普西翁火山的泥石流危害）提供特殊的研究经验。

This project is supported by the Petrology and Geochemistry program (Division of Earth Sciences, Directorate of Geosciences) in cooperation with the Office of International Science and Engineering. Merapi Volcano, located in heavily populated Central Java, is one of Indonesia's most active and dangerous volcanoes. After four years of quiescence, an eruption began on 26 October 2010 that was characterized by explosions along with pyroclastic density current (PDCs) that traveled to the western and southern sectors of the volcano. Reports on 27 October noted that about 35 people died and several were injured. Explosive activity increased during the following days until 4 and 5 November 2010, when a series of large explosions sent various PDCs ~15 km away from the summit, killing more than 300 people. According to the Center of Volcanology and Geological Hazard Mitigation at the Merapi Volcano Observatory, this constitutes the largest eruption at this volcano since 1872, with a current Volcanic Explosivity Index estimated between 3 and 4. These hazardous explosive events present a rare opportunity to collect a uniquely detailed dataset of the source, extent, lateral variations and impact of PDC deposits on a densely populated area. The urgency of the application derives from the ephemeral nature of the pristine deposits associated with these events: these will soon be washed away by the current rainy season in Indonesia and it is rare to have the opportunity to collect key data from such hazardous volcanic flows. The main goals of this RAPID are to collect sufficient data, together with an international team, to: 1) document the sources, duration and runout distances of the different PDCs generated during the 2010 eruptive crisis of Merapi; 2) measure the variations in extent, distribution, morphology, lithology and thickness of the different 2010 PDC deposits using different ground-base techniques; 3) obtain and compute a compilation of spatial images taken prior, during and after the eruption. The effects of topography on flow dynamics will be examined in the field through a Real-Time GPS / Laser Rangefinder survey of the surface of the associated deposits immediately after flow emplacement (once these areas are deemed safe).Collection of such a dataset will be used to generate the pre- and post-eruption numerical topographies for testing the sensitivity to geophysical mass flow model (GMFM) outputs for various qualities of digital representations of natural terrain. A high-resolution benchmark DEM dataset will be computed based on the TanDEM misson-X (roughly 3 m spatial resolution, 1-2 m vertical accuracy). Application of TerraSAR data to generate accurate numerical topographies and/or capturing rapid topographic changes associated with the emplacement of PDC deposits over a short period has tremendous potential benefits to better understand the dynamics of such hazardous volcanic flows. Previous authors have shown the importance of the choice of the DEM on computational routines for reconstructing the different paths, velocities and extents of various flows, and for correctly estimating the areas and levels of hazards associated with future volcanic activity. Data obtained during this project will also be integrated into numerical simulations using freely available GMFMs and allow the validity of these models to be tested, with better quantification of best-fit input parameters. This approach will provide one basis for defining hazard zonations of key areas at risk from PDCs at Merapi, which can be directly integrated into the current hazard mitigation plans at this high-risk volcano. Consequently, the work proposed here will be of immediate benefit to all groups involved in assessing volcano hazards either directly (at observatories on some of the most active volcanoes around the world) or through remote sensing techniques. This project will provide direct support to Sylvain Carbonnier (a post-doctoral Fellow at USF through August 2012) and an exceptional research experience for Jose Armando Saballos (PhD student at USF working on debris flow hazards at Concepcion volcano, Nicaragua).