Traction image method for irregular free surface boundaries in finite   difference seismic wave simulation

doi:10.1111/j.1365-246X.2006.03113.x

CORC > 北京大学 > 地球与空间科学学院

	Traction image method for irregular free surface boundaries in finite difference seismic wave simulation
	Zhang, Wei ; Chen, Xiaofei
刊名	geophysical journal international
	2006
关键词	finite difference MacCormack scheme seismic wave simulation stress image method topography traction image method PLANAR FREE-SURFACE VELOCITY-STRESS COMPUTATIONAL ACOUSTICS PSEUDOSPECTRAL METHOD HETEROGENEOUS MEDIA DYNAMIC RUPTURE HIGH-ACCURACY HALF-SPACE PROPAGATION TOPOGRAPHY
DOI	10.1111/j.1365-246X.2006.03113.x
英文摘要	In this study, we propose a new numerical method, named as Traction Image method, to accurately and efficiently implement the traction-free boundary conditions in finite difference simulation in the presence of surface topography. In this algorithm, the computational domain is discretized by boundary-conforming grids, in which the irregular surface is transformed into a 'flat' surface in computational space. Thus, the artefact of staircase approximation to arbitrarily irregular surface can be avoided. Such boundary-conforming gridding is equivalent to a curvilinear coordinate system, in which the first-order partial differential velocity-stress equations are numerically updated by an optimized high-order non-staggered finite difference scheme, that is, DRP/opt MacCormack scheme. To satisfy the free surface boundary conditions, we extend the Stress Image method for planar surface to Traction Image method for arbitrarily irregular surface by antisymmetrically setting the values of normal traction on the grid points above the free surface. This Traction Image method can be efficiently implemented. To validate this new method, we perform numerical tests to several complex models by comparing our results with those computed by other independent accurate methods. Although some of the testing examples have extremely sloped topography, all tested results show an excellent agreement between our results and those from the reference solutions, confirming the validity of our method for modelling seismic waves in the heterogeneous media with arbitrary shape topography. Numerical tests also demonstrate the efficiency of this method. We find about 10 grid points per shortest wavelength is enough to maintain the global accuracy of the simulation. Although the current study is for 2-D P-SV problem, it can be easily extended to 3-D problem.; Geochemistry & Geophysics; SCI(E); 43; ARTICLE; 1; 337-353; 167
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/156028]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Zhang, Wei,Chen, Xiaofei. Traction image method for irregular free surface boundaries in finite difference seismic wave simulation[J]. geophysical journal international,2006.
APA	Zhang, Wei,&Chen, Xiaofei.(2006).Traction image method for irregular free surface boundaries in finite difference seismic wave simulation.geophysical journal international.
MLA	Zhang, Wei,et al."Traction image method for irregular free surface boundaries in finite difference seismic wave simulation".geophysical journal international (2006).