SeisMic Observations of deep VolcAnic pRocesses

深层火山过程的地震观测

• 批准号: 443363136
• 负责人: Professor Dr. Georg Rümpker
• 金额: --
• 依托单位: Laboratory of Seismogenesis
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/443363136?language=en
• 关键词: SeisMic; Observations; deep; VolcAnic; pRocesses

We aim to study pre-eruptive processes in the deep parts of plumbing systems in subduction zone volcanoes based on seismological observations. Volcanoes are fed by melts that are generated in the mantle and ascend to the surface through a complex and elusive plumbing system that combines pervasive and focused flows and multi-level reservoirs. The processes in the volcano-magmatic systems can be studied based on their seismological manifestations. Pressure variations caused by magma and gas transport generate specific seismic signals as well as stress variations in the surrounding rock that result in variations of its elastic properties.Largest and most dangerous explosive volcanic eruptions are fed from a few kilometers deep magmatic reservoirs. Currently, most seismological observations reflect the shallow pre-eruptive activity. At the same time fully understanding the functioning of volcanic systems and detecting earliest signs of volcanic re-activation requires observations of the processes in the deep volcanic roots. For this purpose, we will study the Klyuchevskoy Volcanic Group (KVG) in Kamchatka that is the largest and the most active cluster of subduction volcanoes in the world and features the systematic occurrence of deep seismo-volcanic activity.The proposed research will be based on the analysis of two major datasets that perfectly complement each other. First, we will use the data of a large joint German-French-Russian field experiment KISS when more than 80 broadband seismographs operated in the KVG region in 2015-2016 (Shapiro et al., 2017a) and recorded the 2016 Klyuchevskoy eruption including the preparatory phase with unprecedented spatial coverage. We will combine this with the long-term records (partly > 20 years) of the permanent seismic network operated on KVG by our Russian partners, composed today of 25 stations. This dataset contains records of more than 30 strong eruptions (VEI up to 4) of the three major KVG volcanoes: Klyuchevskoy, Bezymiammy, and Tolbachik with most of them being preceded by the deep seismo-volcanic activity.We will analyze the available data with modern seismological methods including time-lapse noise- and earthquake-based monitoring, and measurements of time-variable seismic anisotropy. The results of these investigations will reflect the activity in the plumbing system and its influence on the mechanical properties of the crust. They will be used to constrain and quantify the underlying physical processes based on geophysical fluid dynamics models of viscous flow in porous media analysed by our collaborators. As main scientific results, we anticipate developing a comprehensive physical model of the processes controlling the magma ascent from the deep parts of magmatic systems towards the surface and a set of seismological methods that can be used to monitor these deep-seated pre-eruptive processes.

我们旨在根据地震学观察结果研究俯冲带火山中管道系统深部的爆发前过程。火山是由地幔中产生的熔体喂养的，并通过一个复杂且难以捉摸的管道系统升至表面，该系统结合了普遍和集中的流量和多层储层。可以根据其地震学表现来研究火山磁系统中的过程。由岩浆和气体传输引起的压力变化会产生特定的地震信号以及周围岩石的应力变化，从而导致其弹性特性的变化。最大，最危险的爆炸性火山喷发是从几公里的深岩石储层中喂养的。目前，大多数地震学观察结果反映了浅爆发活动。同时，完全了解火山系统的功能并检测最早的火山重新激活迹象，需要观察深火山根中的过程。为此，我们将研究Kamchatka中的Klyuchevskoy火山群（KVG），该群是世界上最大，最活跃的俯冲火山群，并具有系统的系统出现。深厚的Seismo-volcanic活动的系统将基于两个完美互补的主要数据集的分析。首先，当2015 - 2016年在KVG地区运行的80多个宽带地震仪（Shapiro等人，2017a）并记录了2016年的Klyuchevskoy爆发，包括没有预定的空间覆盖的预备阶段，我们将使用一个大型联合德国 - 俄罗斯野外实验吻的数据（Shapiro等人，2017a）。我们将与我们的俄罗斯合作伙伴在KVG上运行的永久地震网络的长期记录（部分> 20年）结合使用，该网络今天由25个站组成。 This dataset contains records of more than 30 strong eruptions (VEI up to 4) of the three major KVG volcanoes: Klyuchevskoy, Bezymiammy, and Tolbachik with most of them being preceded by the deep seismo-volcanic activity.We will analyze the available data with modern seismological methods including time-lapse noise- and earthquake-based monitoring, and measurements of time-variable seismic各向异性。这些研究的结果将反映管道系统的活性及其对地壳机械性能的影响。它们将用于根据我们的合作者分析的多孔培养基中的粘性流动流动的地球物理流体动力学模型来限制和量化潜在的物理过程。作为主要的科学结果，我们预计将开发一种从岩浆系统的深层到表面的岩浆上升的过程的综合物理模型，以及一套可用于监视这些深座的喷发前过程的地震学方法。