Deadly vapors.(ENERGY)

Off the northeast coast of Scotland, 100 miles or so out from Aberdeen, is a mysterious portion of the North Sea known as the Witch Ground. Like the more infamous Bermuda Triangle, legends speak of ships disappearing into the area, never to be seen again. The sea floor below is pockmarked with strange craters. One of the largest, called the Witch's Hole, is located near the southern edge of the mysterious area. There, a survey from the 1970s indicated that something strange was located in the center of the hole.

This got the attention of Alan Judd, a marine geologist from the University of Sunderland. Judd believed the mysterious object to be a ship and embarked on an expedition to prove it. Sending a submersible down to investigate, Judd and his researchers watched on video screens in the mother ship above as the lights of the sub illuminated what turned out to be an 80-foot-long steam trawler sitting placidly upright, and apparently without damage of any kind, in the center of the Witch's Hole. No one knew how she came to be there, but Judd has a theory: methane gas.

According to Judd, the rugged pockmarks are evidence of recent releases of methane from the sea floor. "It is tempting to suggest that it is evidence of a catastrophic gas escape in the not too distant past," he told New Scientist in 2000. What's more, the gas releases, which would markedly reduce the density of seawater where they occur, could have led to the sinking of the trawler. "Any ship caught above would sink as if it were in a lift shaft," Judd ...