Investigation of fluid-controlled seismicity in a swarmquake area

流体在任何类型的地震(诱发的、构造的、深部的、浅部的、大的、小的)的破裂和/或启动过程中的重要作用是毋庸置疑的。然而，流体和相关参数影响应力状态从而影响特定地区地震活动的特殊机制还没有被很好地理解。流体被认为在板内震群中起主导作用，与构造活动区相比，板内地震群的变形速度较小。在这里，我们建议对德国东南部巴德赖琴霍尔群震区的地震时空行为、与流体有关的参数(例如地下水位)和大气可观测性(例如降雨量、大气压力)进行广泛的研究。除了1995年记录的数百次小规模地震的数据集外，2000年在研究区安装的永久地震台网还允许收集几个震群的数据，最后一次是在2002年8月的暴雨(在德国造成毁灭性的洪水)之后不久，发生了500多次地震事件。这项研究的目的是试图(定量)回答降雨量、融雪、地下水位、压力(梯度)、覆盖层压力是否(以及如何)与观测到的地震活动在空间和时间上的模式存在因果关系。拟议的研究区的主要好处是(1)地震发生的受限体积；(2)频繁发生的震群；(3)由巴伐利亚州独立支持的研究区内的一个永久监测的现代近实时网络。

The important role of fluids in the rupture and/or initiation process of any kind of earthquakes (induced, tectonic, deep, shallow, large, small) is undisputed. Yet, the particular mechanisms through which fluids and associated parameters influence the stress regime and thus the seismicity of a particular area are not well understood. Fluids are thought to play a dominant role of intraplate earthquake swarms where the deformation rate is small compared to tectonically active regions. Here, we propose to carry out an extensive study of the spatio-temporal behavior of earthquakes, fluid-related parameters (e.g. ground water levels) and atmospheric observables (e.g. rainfall, atmospheric pressure) in the swarmquake area of Bad Reichenhall, in the southeast of Germany. In addition to a data set with several hundred small earthquakes recorded in 1995, a permanent seismic network installed in the study area in the year 2000 allowed the collection of data from several earthquake swarms, the last of which followed shortly after the heavy rainfall in August 2002 (causing the devastating floods in Germany) with more than 500 seismic events. The goal of this study is to attempt to give a (quantitative) answer whether (and how) rainfall, snowmelt, ground-water level, pressure (gradients), overburden pressure, are causally related to the observed seismicity patterns in space and time. The major benefits of the proposed study area are (1) the confined volume in which the earthquakes take place; (2) the frequently occuring earthquake swarms; and (3) a permanently monitoring, modern near-real time network in the study area independently supported by the Bavarian state.