PREDICTION OF REGIONAL STRESS AND CONSTITUTIVE RELATIONS BASED ON INVERSE ANALYSIS OF GPS DATA

本研究的目的是通过分析全国GPS测量的位移和应变数据，预测区域应力和本构关系。1)从理论上证明了位移增量对应于板块运动引起的地壳整体变形，而应变增量代表了产生特定区域变形的区域非均质性。2)为了预测地壳整体变形，提出了一种基于谱分解的反分析方法。该方法的主要特点是综合考虑测量精度来确定地壳整体形变的可测量模式，并利用测量数据预测模式和相关的震源。3)对于区域地壳形变的预测，建立了平均应变增量的计算公式，并利用应力逆…在此基础上，提出了一种新的应力增量估算方法。该公式给出了由三个GPS站组成的三角形区域的平均应变，而不求导数。应力反演法是利用艾里应力函数确定处于平衡状态的应力分量，利用实际GPS网数据进行的数值分析表明，利用这些方法可以预测区域应力和本构关系。区域应力增量和本构关系的预测值是合理的，尽管结果的有效性没有得到验证。结果表明，该分析方法适用于高空间分辨率GPS网数据的新数据分析方法。因此，预计本研究将继续进行，并正在开发使用这些方法的所谓地壳形变监测仪。并计划通过与地壳结构和地震事件的对比来验证分析的有效性，并将该方法推广到未来的地壳形变预测。较少

This research is aimed at predicting regional stress and constitutive relations, by analyzing the displacement and strain data that are measured by the nation-wide GPS data. The following three are the major results :1) It is theoretically shown that the displacement increment corresponds to the overall crustal deformation caused by the plate movement, while the strain increment represents the regional heterogeneity that produces particular regional deformation.2) For the prediction of the overall crustal deformation, an inverse analysis method using the spectral decomposition is thus proposed. The key feature of this method is that measurable modes of the overall crustal deformation is determined by considering the accuracy of the measurement, and the modes and the associated source are predicted by using the measured data.3) For the prediction of the regional crustal deformation, the formulae to compute the average strain increment is developed and the utilization of the stress inver … More sion method is proposed to estimate the stress increment. The formulae gives an average strain taken over a triangular region formed by three GPS station without taking derivatives. The stress inversion method is to determine stress components which are in equilibrium, by making use of Airy's stress function.It is shown in numerical analysis that uses the actual GPS network data that the regional stress and constitutive relations can be predicted by using these methods. The predicted values of the regional stress increment and constitutive relations appears reasonable, even though the validity of the results are not verified. However, it is surely shown that the analysis method work for new data analysis methods of the GPS network data which are measured in high spatial resolution. Therefore, the continuation of the present research is expected, and a so-called crustal deformation monitor that uses these methods is being developed. Also, it is planned that the validity of the analysis is verified by comparing with the crust structure and the seismic event, and that the method is extended to predict future crustal deformation. Less