Comparative analysis of resistance and applicability of several commonly used strain calculation methods
Strain rate is one of the main parameters to characterize crustal deformation,which can be used to identify crustal deformation characteristics before and after strong earthquakes and is of great significance to understand the process of seismicity breeding and to advance the research of earthquake prediction.Different strain calculation methods have different applicability for different research purposes and data distribution densities.The robustness and applicability of four different strain calculation methods such as Voronoi,spherical wavelet,distance weighting and least square collocation are analyzed for different spatial scales by using simulation data.The results of resistance analysis on large spatial scale show that the least square collocation method has the strongest resistance,followed by distance weighting and spherical wavelet method,and the attenuation rate of correlation coefficient of Voronoi method is significantly faster than the other three methods.In the case of removing part of the sampled data,the Voronoi method has too much influence on the calculation result because of the noise,and the results of the other three methods are consistent.Comparative analysis of medium spatial scale shows that the residual mean square error of least square collocation and distance weighting is significantly smaller than that of the other two methods.The edge effect of Voronoi method is obvious,the spherical wavelet method has a certain deviation from the theoretical solution,the least square collocation and distance weighting method are consistent with the theoretical solution,but the former has a deviation from the theoretical solution in the deformation magnitude and spatial resolution,and the latter has a deviation from the theoretical solution in the fast deformation region.The results of comparative analysis based on the GNSS observation data from the China Crustal Movement Observation Network show that the edge effect of Voronoi method is obvious.The distance weighting method has local edge effect.The spherical wavelet method can reflect the influence of faulting well,but there are many local high value areas.The least square configuration method can take into account the near and far field deformation characteristics of faults.Different methods have obvious differences in sensitivity to error,edge effect,local singular distribution,etc.In practical application,it is necessary to adopt the method with strong resistance,stable results and not obvious edge effect.
万方数据
维普
