Time domain viscoelastic forward modeling on GPU

We implement an efficient time domain viscoelastic forward modeling using Graphics Processing Unit (GPU). A staggered finite difference scheme of second-order temporal accuracy and fourth-order spatial accuracy with the unsplit convolutional perfectly matched layer (CPML) is applied to the 2D viscoelastic stress-velocity wave equations. To calculate the relaxation times for pressure wave and shear wave in wave equations, the τ-method is used to approximate a constant Q over the frequency band of the source. The numerical results indicate that the CPML can efficiently absorb waves reaching the absorbing layers at grazing incidence. And our GPU-based viscoelastic forward modeling tests achieved a speedup of a factor 10 relative to a CPU implementation.