Propagation of Torsional Surface Waves in Dry Sandy Medium under Gravity

Abstract

This paper studies the possibility of propagation of torsional surface waves in a gravitating earth with a dry sandy medium. The mathematical analysis of the problem has been dealt with in the Whittaker function. Assuming the expansion of the Whittaker function to linear terms, it is concluded that the gravity field will always allow torsional waves to propagate. The expansion of the Whittaker function to quadratic terms shows that two such wave fronts may exist. Finally, it is concluded that the sandy medium without support of a gravity field cannot allow the propagation of torsional surface waves, whereas the presence of a gravity field always supports the propagation of torsional surface waves regardless of whether the medium is elastic or dry sandy.