These were questions that also intrigued Hardy Pfanz, a volcano biologist from Germany's University of Duisburg-Essen who studies geogenic gases – gases given off during... moreThese were questions that also intrigued Hardy Pfanz, a volcano biologist from Germany's University of Duisburg-Essen who studies geogenic gases – gases given off during geological processes. "When I read the descriptions from the ancient writers, I began wondering if there could be a scientific explanation," he said. "I wondered, could this Gate to Hell be a volcanic vent?"