A Seismic Forward Modeling Program

Seismic forward modeling programs serve as essential tools in geophysical exploration, capable of simulating seismic wave propagation through subsurface media. For beginners, understanding the fundamental principles and implementation methods of seismic forward modeling represents a critical first step into this field.

Seismic forward modeling programs are typically based on wave equations, such as acoustic wave equations or elastic wave equations, solving wavefield propagation through numerical methods like finite difference schemes. When implementing in MATLAB, the key steps include:

Model Construction: Define physical parameters of subsurface media, such as velocity and density, typically represented as 2D or 3D matrices using MATLAB's array operations. Code implementation involves creating parameter grids with appropriate spatial sampling.

Initial and Boundary Conditions: Configure source functions (e.g., Ricker wavelets) using mathematical function implementations, along with absorbing boundary conditions (such as PML) to minimize artificial reflections. This requires careful parameter tuning in the code.

Numerical Solution: Employ finite difference methods for iterative computation of wavefield evolution in time and space. The core algorithm involves time-stepping schemes (explicit/implicit) and spatial difference calculations using discrete differential operators. MATLAB optimization techniques can significantly improve computational efficiency.

Result Visualization: Display wavefield snapshots or seismic records through images or animations using MATLAB's plotting functions (imagesc, movie, etc.), facilitating analysis of wave propagation characteristics.

For beginners, understanding the program's modular design—including parameter initialization, wavefield updating, and boundary handling—is crucial. Mastering MATLAB's matrix operations and loop optimization techniques (vectorization) can substantially enhance program performance.

By implementing a basic seismic forward modeling program, beginners not only learn wave theory but also become familiar with fundamental numerical simulation workflows, laying groundwork for advanced research in complex problems like anisotropic media or reverse time migration.