the heat blasting from the ` ring of fire ' has been measured at 792c -lrb- 1457f -rrb- from two metres away , reports people 's daily online , and is so intense that experts ca n't get close enough to determine how deep the hole is .
the temperature has been measured at 792c - but that was from two metres away .
experts think a coal seam may have spontaneously combusted below ground .