Studies of Unusual Earthquakes: Volcanos and Landslides

异常地震研究：火山和山体滑坡

• 批准号: 0944055
• 负责人: Goran Ekstrom
• 金额: $ 24.75万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0944055&HistoricalAwards=false
• 关键词: Studies; Unusual; Earthquakes; Volcanos; Landslides; Studies; Unusual; Earthquakes; Volcanos; Landslides

The project involves the investigation of anomalous seismic sources with a specific focus on slow earthquakes associated with volcanos and landslides. It builds on results and discoveries that have come from the systematic application of a long-period event detection algorithm to real-time and archive seismic data recorded on the Global Seismographic Network. For each year since 1991, more than 100 earthquakes of magnitude 5 or greater that are not reported in other catalogs have been detected and located using this algorithm. Many of these earthquakes are slow, and a large number of them have been associated with volcanos and landslides. The first goal of the project is to discriminate volcano and landslide earthquakes from other earthquakes that have been identified only by the long-period detection algorithm. The second goal is to relate those earthquakes that occur in volcanic regions to eruptive activity and changes in the geometry and behavior of magmatic plumbing systems. In particular, the project will involve a detailed comparative study of unusual earthquakes associated with the two greatest caldera collapses of basaltic volcanos over the last century, Fernandina (Galapagos Islands) and Miyakejima (Japan). The third goal is to investigate anomalous earthquakes associated with large landslide events. A recently developed methodology for determining the trajectory of the sliding mass during a landslide directly from the radiated seismic waves will be refined and improved and applied to several known and inferred landslide events in order to estimate dynamic landslide parameters.The project will lead to an improved characterization and discrimination of earthquake sources, and will help clarify the phenomenology of volcano and landslide earthquakes. The volcano investigations will provide new constraints on stress and deformation patterns within active volcanoes, as well as on the mechanics of caldera collapse and its relationship to magmatic transport and plumbing. The landslide investigations will lead to better characterization of the seismic radiation from landslide sources, and will provide new constraints on key landslide parameters, such as mass, runout, and effective coefficient of friction. The seismological analysis methods developed for these studies will contribute to improved monitoring capabilities for volcanos and landslides, which represent important classes of geohazards.

该项目涉及对异常的地震来源进行调查，其特定关注与火山和滑坡相关的缓慢地震。它建立在从全球地震网络上记录的实时和档案地震数据中的长期事件检测算法的系统应用中的结果和发现。自1991年以来，每年都已经检测到并使用该算法发现了100多个在其他目录中未报告的地震5或更高地震。这些地震中有许多是缓慢的，其中许多地震与火山和滑坡有关。该项目的第一个目标是将火山和滑坡地震与仅由长期检测算法确定的其他地震区分。第二个目标是将发生在火山区域中的地震与喷发活动以及岩浆管道系统的几何形状和行为变化联系起来。特别是，该项目将涉及与上个世纪的两种最大火山口倒塌相关的异常地震的详细比较研究，即加拉帕戈斯群岛（Galapagos Islands）和Miyakejima（日本）。第三个目标是研究与大型滑坡事件相关的异常地震。最近开发的方法是直接从辐射的地震波中确定滑坡期间的滑动质量轨迹，将进行完善和改进，并应用于几个已知和推断的滑坡事件，以估算动态滑坡参数。该项目将带来改进的地球界面和地球来源的范围，并有助于地球界的界限，并将批准批准。火山调查将对活跃火山内的应力和变形模式以及火山口倒塌的机制及其与岩浆运输和管道的关系提供新的限制。滑坡的调查将导致从滑坡来源更好地表征地震辐射，并将对关键滑坡参数（例如质量，跳动和有效的摩擦系数）提供新的限制。这些研究为这些研究开发的地震分析方法将有助于改善火山和​​滑坡的监测能力，这代表了地质阵径的重要类别。