This hydrothermal vent emits black smoke. Hydrothermal vents are fissures in the earth's surface, often found in volcanically active areas. Undersea vents support unique and diverse ecosystems. The base of the food chain in submarine undersea vents is chemosynthetic bacteria fed by chemicals dissolved in the vent fluid. Courtesy of Volcanoes of the Deep Sea/Rutgers University/Newscom/File
Tube worms feed at the base of a black smoker chimney hydrothermal vent. Tube worms are found at depths from 100 to 10,000 meters under the ocean. They survive through symbiotic relationships with chemosynthetic bacteria which live inside them. NOAA
A close up view of tubeworms at a seafloor hot spring on Daikoku volcano, in the northern part of the Mariana volcanic arc. These animals only live at hydrothermal vents and were not discovered until 1900. Pacific Ring of Fire 2004 Expedition/NOAA
The Kiwa hirsuta, or yeti crab, was discovered in 2005 in the South Pacific. This crab was photographed at 2,300 m depth at the hydrothermal site of the Pacific Antartic Ridge called Annie's Anthill and located south of Easter Island. Robert Vrijenhoek /MBARI Institute/Newscom/File
High temperature white smoker vents, 212°F, are seen at Champagne Vent in the Caribbean. NOAA
Photosynthetic green and red algae is growing on the same rocks as chemosynthetic bacteria near the top of East Diamante volcano. Usually, these two life forms are not found together because one depends on the sun for energy and the other on chemical energy from deepsea hydrothermal vents. Here in the Marana volcanic chain, however, submarine volcanoes come close to the surface. Pacific Ring of Fire 2004 Expedition/NOAA
Shrimp and crabs living near the summit of Northwest Rota-1 volcano graze bacterial mats on the rocks at hydrothermal vents. They also have to watch out for volcanic eruptions at this active submarine volcano. Pacific Ring of Fire 2004 Expedition/NOAA
A black smoker is seen at a mid-ocean ridge hydrothermal vent in the Atlantic Ocean. NOAA
Giant tubeworms congregate in the thousands near hydrothermal vents. Riftia have no mouth or digestive tract, and can grow up to eight feet in length. They form symbiotic relationships with bacteria that live inside them. The bacteria convert hydrogen sulfide given off by the vents into organic molecules that nourish the worm. Courtesy of Woods Hole Oceanographic Institution/Newscom/File
A Vent Crab found 8,000 feet below the ocean surface where it lives around hydrothermal vents, is shown on display in Mystic, Conn. on May 19, 1999. Steve Miller/AP
Foreign media were given rare access Monday to three Americans being held by North Korea. Jeffrey Fowle and Mathew Miller said they expect to face trial within a month. Kenneth Bae, who is serving a 15-year jail term, said his health has deteriorated.
ByEric Talmadge, Associated Press
North Korea gave foreign media access on Monday to three detained Americans who said they have been able to contact their families and — watched by officials as they spoke — called for Washington to send a high-ranking representative to negotiate for their freedom.