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.
Earthquakes generate three types of seismic waves: P (primary) waves, S (secondary) waves and surface waves, which arrive at seismic recording stations one after another.Both P and S waves penetrate the interior of the Earth while surface waves do not. Due to this, P and S waves are known as body waves.arthquakes generate three types of seismic waves: P (primary) waves, S (secondary) waves and surface waves, which arrive at seismic recording stations one after another.