a group of persons, as employees, charged with carrying out the work of an establishment or executing some undertaking. a group of assistants to a manager, superintendent, or executive. a member of a staff.
Seismic waves are the waves of energy caused by the sudden breaking of rock within the earth or an explosion. They are the energy that travels through the earth and is recorded on seismographs. Types of Seismic Waves. There are several different kinds of seismic waves, and they all move in different ways.
Different types of seismic waves include: Surface waves: Seismic waves that travel along the Earthâs surface. Body waves: Seismic waves that travel through the Earthâs interior. There are two types: Primary waves (P waves): Body waves that compress and expand rock in the direction the waves travel (like a slinky). Secondary waves (S waves): Body waves that shake material at right angles to the direction the waves travel (like shaking a rope). Solid rock transmits S waves, but gases and liquids do not.