论文部分内容阅读
近场地震动数据可半实时地或由现代强震台网获得,或由连续全球定位系统(GPS)台网获得,能得到震源参数的稳健可靠解,这助于快速灾害评估及早期预警。这些广泛的应用需要地震动数据覆盖非常宽的频带,然而这通常情况下很难达到。本文是2011年日本东北MW9.0地震的实例研究,说明来自大地测量和地震仪器的地震动信息如何互补,并建议联合使用这两种数据,尤其是台网覆盖稀疏时。本文首先使用自动经验基线校正工具对日本两个台网K-NET和KiK-Net的强震记录进行分析。通过二重积分得到静态同震位移,然后用于导出地震断层上的永久滑动分布。通过与相应基于GPS解的对比,对经验基线校正的不确定性得出了定量估计。另外,选择12对位置邻近的GPS和强震台站进行比较,来说明它们在时间序列中的信息相互一致。最后,讨论联合使用两种地震动观测系统的方法,并重点说明该方法的广泛可行性。
Near-field seismic data can be obtained semi-real-time or from modern strong seismic stations or acquired from a continuous global positioning system (GPS) network, providing a robust and reliable solution to source parameters that contributes to rapid disaster assessment and early warning. These broad applications require that seismic data cover a very wide band, but this is often difficult to achieve. This article is a case study of the 2011 northeastern Japan MW9.0 earthquake that illustrates how ground-motion and ground-based seismic information from seismic instruments complement each other and suggests a combination of these two types of data, especially when network coverage is sparse. This paper first analyzes the strong earthquakes records of two K-NET and KiK-Net networks in Japan using an automatic empirical baseline correction tool. The static coseismic displacements are obtained by double integration and then used to derive the permanent slip distribution on the seismic fault. A quantitative estimate of the uncertainty of the empirical baseline correction is obtained by comparison with the corresponding GPS-based solution. In addition, a selection of 12 GPS and strong ground stations in close proximity is compared to show that their information in the time series is consistent with each other. Finally, we discuss ways to jointly use two types of ground motion observing systems and highlight the broad feasibility of this method.