Seam thickness

No standard can be set conclusively as to whether thick or thin seams are more outburst prone. In theory, seams that are thick and/or steep should be more prone to outburst due to the effects of gravity causing the gas to locate in a specific area. However, evidence points to thin seams being equally prone to outburst, with 573 out of 1,032 outbursts in the Donbass Mine, Ukraine, occurring in seams less than one metre thick. There is also no evidence pointing to seams thicker than 2.3 metres being prone to outburst. (Lama & Bodziony, 1996)