Seismic wave propagation

Refractions and reflections in a two-layered medium

The web site demonstrates SH-wave propagation in a two layer medium (2-D). S-wave velocity of the upper layer is faster than that of the lower layer. Click the left button of the mouse at a point, and the seismic source is fixed. Push the Start bot-ton on the screen, and S wave is radiated at the point. The wave propagates toward the right hand side with the refractions and reflections. The lower panel also shows ground deformation at the surface stations shown by triangles.

After the start of the simulation, you can put additional multiple sources by click of the right bot-ton. Move the source slowly, and the strong wave is radiated toward the right hand side, which is known as "directivity".

Surface

• Start, Pause, Restart: push the s button of the keyboard, or push the button of "Start/Pause" on the screen.
• Left button: Locate an initial seismic source
• Right button: Locate seismic sources after the simulation
• Upper boundary is free surface, and the other boundaries are absorption boundaries.