地震工程学报Issue(1)：214-221,8.DOI:10.3969/j.issn.1000-0844.2015.01.0214
结合欧拉矢量的反演算法构建青藏高原东北缘地壳运动速度场模型
Using an Inversion Algorithm with Euler Vector to Construct a Model of the Crustal Movement Velocity Field in the Northeastern Margin of the Tibetan Plateau
摘要
Abstract
Many methods and models have been used to construct crustal movement velocity fields,including Least Squares Collocation,multi-surface functions,spherical harmonics methods, spherical discontinuous deformation analysis,and finite element methods,all of which have certain premise conditions or application scope.Based on the Euler vector,we put forward a new particle swarm optimization (PSO)algorithm from which block motion and strain tensor parameters can be determined by inversion,and then a regional crustal movement velocity field can be construc-ted.Simulation test results showed that this improved PSO is stable and effective.When the itera-tion reached 20 times,the improved PSO results were close to their optimal values,while the oth-er two algorithms continued to search.The precision of the velocity field constructed by this meth-od is much higher than that from linear and nonlinear PSOs.A comparison of the effectiveness and lack of bias of the displacement calculated by different methods indicated that the accuracy of the velocity model calculated by the improved PSO was the highest,and the variance and mean value of its residuals were much smaller.Based on GPS observational results from the northeastern mar-gin of the Tibetan Plateau from 1 999 to 2013,for which coseismic disturbance has been considered on the basis of block division and model identification evaluated by unbiased and effectiveness rules,the crustal movement velocity field was determined using the improved PSO.The residual characteristics that closely followed a normal distribution indicated that the velocity field calculat-ed by the improved PSO was reliable and without systematic error.A comparison with the results calculated by Least Squares Collocation was performed,which indicated that the new PSO algo-rithm effectively and accurately established the crustal movement velocity field.From the con-structed velocity field,a significant difference can be seen in how the northeastern margin of the Tibetan Plateau crust moves;the velocity decreases from south to north with clockwise rotation. The NE motion is blocked by the relatively stable Alashan block,which is creating mountain up-lift and basin subsidence in the region.关键词
地壳运动/速度场模型/粒子群算法/青藏高原东北缘/反演Key words
crustal movement/velocity field model/particle swarm optimization/northeastern margin of the Tibetan Plateau/inversion分类
天文与地球科学引用本文复制引用
王帅,张永志,姜永涛..结合欧拉矢量的反演算法构建青藏高原东北缘地壳运动速度场模型[J].地震工程学报,2015,(1):214-221,8.基金项目
国家自然科学基金(41374028,40674001) （41374028,40674001）
国土资源大调查项目(1212010914015) （1212010914015）
陕西省教育厅自然科学科研项目(12JK0798) （12JK0798）
