Plane shear wave emitted into elastic half space by an oscillating nonuniform normal pressure

Excitation of an elastic half space by an oscillating normal load nonuniformly distributed over its surface is considered. The medium is assumed to be linear, isotropic and homogeneous. Exterior load distribution is smooth and the scale of its variation is small compared to wave lengths. A simple expression is found describing the shear wave with a plane front running away from the surface. This wave vanishes when the load is taken uniform.