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

该项目由岩石学和地球化学项目(地球科学司、地球科学局)与国际科学和工程办公室合作提供支持。默拉皮火山位于人口稠密的爪哇中部，是印尼最活跃、最危险的火山之一。在沉寂了四年之后，2010年10月26日开始喷发，其特点是爆发，同时火山碎屑密度流(PDC)流向火山的西部和南部。10月27日的报告指出，大约35人死亡，数人受伤。在接下来的几天里，爆炸活动有所增加，直到2010年11月4日和5日，一系列大爆炸使各种营地远离山顶约15公里，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说法，这是自1872年以来这座火山最大的一次喷发，目前的火山爆炸性指数估计在3到4之间。这些危险的爆炸事件提供了一个难得的机会来收集关于PDC矿床的来源、范围、横向变化和对人口稠密地区的影响的独特详细的数据集。申请的紧迫性源于与这些事件有关的原始沉积物的短暂性质：这些沉积物很快就会被印度尼西亚当前的雨季冲走，而且很少有机会从这种危险的火山流中收集关键数据。这次快速调查的主要目标是与一个国际小组一起收集足够的数据，以便：1)记录2010年默拉皮火山喷发危机期间产生的不同PDC的来源、持续时间和运行距离；2)使用不同的地面技术测量2010年不同PDC矿床的范围、分布、形态、岩性和厚度的变化；3)获取和计算在喷发之前、期间和之后拍摄的空间图像。地形对水流动力学的影响将通过在水流就位后立即(一旦这些地区被认为是安全的)相关沉积物表面的实时GPS/激光测距仪测量在野外进行检验。收集这样的数据集将被用来生成喷发前和喷发后的数值地形，用于测试自然地形的各种质量的数字表示对地球物理质量流模型(GMFM)输出的敏感性。高分辨率基准DEM数据集将基于串联MISSON-X(大约3米空间分辨率，1-2米垂直精度)进行计算。应用TerraSAR数据生成准确的数字地形和/或捕捉与PDC矿床在短期内就位有关的快速地形变化，对于更好地了解这种危险火山流动的动态具有巨大的潜在好处。以前的作者已经证明了在计算程序上选择DEM的重要性，以重建不同流动的不同路径、速度和程度，并正确估计与未来火山活动相关的危险区域和级别。在该项目期间获得的数据还将被纳入使用免费提供的GMFM的数值模拟中，并允许对这些模型的有效性进行测试，以更好地量化最佳匹配的输入参数。这一方法将为确定默拉皮火山保护区面临风险的关键地区的危险区划提供一个基础，这些危险区划可直接纳入这座高风险火山的当前减灾计划。因此，这里提议的工作将对参与直接(在世界上一些最活跃的火山的观测站)或通过遥感技术评估火山危害的所有小组立即受益。该项目将为Sylvain Carbonnier(2012年8月在USF担任博士后)提供直接支持，并为Jose Armando Saballos(USF在尼加拉瓜康塞普西翁火山从事泥石流危险研究的博士生)提供非凡的研究经验。

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).