This paper categorises the different types of coal bursts and gas outbursts in terms of their mechanisms. It is considered to be essentially impossible to predict when one of these events may occur. However, it is possible in many of the cases to predict the velocity of ejection and hence the distance with which particles may travel including bouncing and rolling and sliding. Keeping beyond this stand-off distance ensures the safety of workers from impact. Where gassy fault gouge exists there is no such safe distance. The material involved may be ejected in the form of a turbulent flow which has been described as a coal storm and which can travel great distances. This also involves large amounts of gas with the inherent problems of explosive mixtures. Locating, and determining the size of such geological features is therefore of great importance. Methods of doing this are discussed
