The gas continually escapes because of faulting, so if you strike a match, flames appear from the ground and spread about in all directions. It's especially awe-inspiring in winter and spring, when the weather is drier.
「出火」的地質是泥岩層，地底富含天然氣，點火後即形成出火景觀，而且火苗四處游移，尤其在冬、春乾季時更是壯觀。