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.
Introduction. Earthquake waves are seismic waves that are created when energy builds up in rocks and they fracture. Scientists estimate there are several million earthquakes each year. Every earthquake produces P waves and S waves but only larger earthquakes produce Love waves and Rayleigh waves.