propagation of a plane wave

Propagation of a Plane Wave

Plane Wave Approximation from a Spherical Front

Displacements for P and S waves

Radial and Transverse Motion of P and S Waves

Radial and Transverse Energy

N-S and EW components have nearly equal amplitude and energy (BAZ is 323o)

Rotate the seismogram to produce Radial and TransverseTransverse components

SKS and SKKS are P to Sv converted phases and are strongest on Radial

Sdiff has mostly Sh energy and is strongest on Transverse

Particle Motion

If we plot the particle motion for the Radial versus the Transverse component The SKS phase shows the most energy on the Radial The Sdiff phase shows the most energy on the Transverse

S wave delays

Note the S wave arrival times on the N-S and the E-W components.Are they coincident ?Why or Why not ?If you see a time delay or offset, what is causing this ?

Seismic and Mineral Anisotropy

P and S wave differences

Effects of Ground Composition on Seismic Energy

Seismometer ground displacements from 1989 Loma Prieta earthquake Magnitude 5 aftershock Seismometer on solid bedrock (above)Seismometer on filled land (below)