spheroidal vibration

seismology

Learn about this topic in these articles:

In earthquake: Long-period oscillations of the globe
…type, called S modes, or spheroidal vibrations, the motions of the elements of the sphere have components along the radius as well as along the tangent. In the second type, which are designated as T modes, or torsional vibrations, there is shear but no radial displacements. The nomenclature is _nS_l…
Read More