Study of Anomalous Wavetrains Associated with Long-Period Spheroidal Mode Overtones

点击翻译按钮获取中文摘要

This is a proposal for a new project in which is studied anomalous wavetrains associated with long-period spheroidal mode overtones. The proposed projects include: (A) Observation of anomalous wavetrains using Global Digital Seismograph Network (GDSN) and GEOSCOPE records. We will use a stacking technique (UC contours) to separate modes and examine particle motion tracings to identify anomalies. A compilation of data sets of anomalous wavetrains caused by the path effects is essential. (B) Analysis of path-dependent dispersion relations. Our preliminary study of anomalous surface wave overtones indicates that this problem is spatially dependent on the path. In this case the local dispersion relation does not determine the modes of waves. Instead we should consider an expression that depends on the properties of the mode over its entire range of wave propagation, so we can use the results to construct the overall eigenvalues for the system. (C) Collaboration through a work station network. Our proposed study of surface wave propagation requires a knowledge of the earth's structure which may also be supplied by tectonic, geodetic and geological studies. We will exchange data, information and ideas related to the earth's structure with scientists in different fields through a work station network.