| Research Abstract |
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
|
