GNSS多尺度应变场估计及区域形变检测

利用GNSS数据,基于球面小波构建了GNSS多尺度应变场的估计模型,给出了球面小波位置和尺度的选取、模型正则化因子和参数的估计方法。为检验所构建模型的正确性,根据负位错理论正演了震间闭锁断层区域地表速度场作为模拟数据源,估计并分析了闭锁状态下走滑断层区域应变场分布特征,结果与实际吻合。模拟不同空间影响范围的闭锁逆冲断层形变,开展了多尺度应变场检测不同空间尺度形变信息的试验。结果表明,对于50km影响范围的小断层形变信号,在大尺度(第4—7尺度)应变场中并没有体现。而在小尺度(第8尺度)应变场中表现得非常明显。对于150km影响范围的大断层形变,在小尺度(第8尺度)应变场中仅出现了一小部分信息,而在大尺度(第4—7尺度)应变场中表现得更加完整和明显。由此得出,不同空间影响范围的地壳形变信息会在相应尺度的应变场中得以体现;小尺度应变场具有检测局部地壳形变信息的优势。

Estimation of GNSS Multiscale Strain Field and Detection of Regional Crustal Deformation

Using GNSS data,the estimation model for GNSS multiscale strain field was established based on spherical wavelet.The key technologies for wavelet center location,wavelet scale choices and regularization parameter calculation were discussed in detail.For further testing the correctness of the model,the simulated data in locked fault areas was generated according to negative dislocation theory. With spherical wavelet model,the strain field in locked strike-slip fault areas was estimated,and the results agreed well with the characteristics of actual crustal deformation.Meanwhile,the experiments on crustal deformation anomaly detection with multiscale strain field were completed.The results showed that the small fault deformation of 50 km appeared obviously in the small scale(8th scale)stain field,but there wasn’t signals in the large scale (4 to 7 scale).The large fault deformation of 150 km only showed a part of information in the small scale (8th scale)stain field,but showed more completely and clearly in the large scale(4 to 7 scale).So it’s concluded that crustal deformation of different spatial coverage scope embody in the different scales strain field,and the small scale strain field have the ability to detect regional deformation anomaly.