Pacific Ring of Fire's Danger Zone
The Devil's Sea, or Dragon's Triangle, is an area of the Pacific Ocean south of Tokyo, roughly between the Izu Islands and the Ogasawara Islands. Its reputation was popularized in the 1970s and 1980s by American author Charles Berlitz, who connected it to the Bermuda Triangle. The region sits directly on the Pacific Ring of Fire, a zone of intense tectonic activity. The Philippine Sea Plate is actively subducting beneath the Eurasian Plate at a rate of at least 4 centimeters per year, creating significant undersea volcanic and seismic events. This geological instability is the main source of the area's verifiable hazards.
One of the most cited incidents is the disappearance of the Japanese research vessel Kaiyo Maru No. 5 on September 24, 1952. The ship, with 31 crew and scientists aboard, was dispatched to investigate the eruption of an undersea volcano, Myōjin-shō. Debris from the vessel was later found, and the official cause of its loss was determined to be the volcanic eruption. Many of the other vessels reported lost by Berlitz were small fishing boats, often with poor or no radio equipment, that succumbed to the region's notoriously severe weather, which includes sudden storms and typhoons.
The Science of Sinking
The seafloor in the Dragon's Triangle contains vast deposits of methane hydrates, ice-like structures that trap methane gas under the high pressure and low temperatures of the deep sea. Japan's surrounding sea areas are known to have abundant reserves of this "fiery ice." Seismic activity or changes in water temperature from undersea volcanic vents can destabilize these hydrates. This triggers a rapid release of methane gas.
A massive eruption of gas bubbles can dramatically lower the density of the water. For a ship sailing directly overhead, the effect is catastrophic. Buoyancy depends on the density of the fluid; if the water suddenly becomes a froth of gas, it can no longer support the ship's weight. The vessel would effectively fall through the aerated water, sinking almost instantly without time to send a distress signal, leaving no trace on the surface. This "ocean flatulence" phenomenon is a likely scientific explanation for some sudden disappearances. The region's volcanic geology can create magnetic anomalies. Variations in the magnetic fields of the seafloor rocks can potentially interfere with traditional magnetic compasses, contributing to navigational errors.