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.
Seismic waves are of two types the P waves and the S waves. The P  waves are the first stronger waves that travel through solids and  liquids and the S waves are the follow â¦ up waves that can travel  only through solids. The velocity of the waves depends on the  nature of medium it travels through.