Coal mine rescue and survival system

A system is described which is designed to cope with emergency situations by providing means for survival, communication, and rescue. The system has two parts- an electromagnetic system that provides through- the- earth radio transmission of voice or beacon messages, and a seismic system that enables rescuers to detect and locate vibrations produced by pounding with a pick, sledge hammer or other heavy object. Use of the two systems allows the maximum chance for communications by providing redundant modes of operation and by taking into account all means by which a trapped miner could communicate with rescuers.