New hydrothermal vents discovered as 'South Pacific Odyssey' resea...( reports by on-scene science writers and...)

MORE ABOUT THE LAU BASIN

The Lau Basin, a 390-kilometer stretch of the ocean basement about the length of Taiwan, has captured the interest of scientists since the late 1960s. Lined with active deep-sea volcanoes and hydrothermal vents--along with massive sulfide deposits enriched in gold and other minerals--it is home to gigantic snails and other strange animals that live in total darkness off of the hot, acidic vent water. Many scientists have dubbed the basin "the perfect geologic experiment," an ideal place to study the processes that connect Earth's deep interior to ocean ridge volcanoes and the biological communities they support in the complete absence of sunlight.

The Lau Basin is flanked by two underwater mountain ridges that sit roughly between Fiji in the west and the Kingdom of Tonga in the east; the ridges run south toward New Zealand. "We are fortunate to have the full support of the Kingdom of Tonga, as our research area is in its territorial waters," said Fisher. The Kingdom of Tonga is dubbed "the land where time begins" because of its location immediately west of the International Dateline. Tongans are the first in the world to greet the dawn of a new day.

"The Lau Basin was chosen by the U.S. research community as the best place in the world to study the links between the geology, chemistry, and biology of a back-arc spreading center and to understand the large-scale cycling of materials from the seafloor to the Earth's interior and back again," Fisher said.

The Lau Basin site is unique by virtue of its being a back-arc basin, where spreading splits the ocean floor apart very close to a volcanic arc. The way the geology works in a back-arc basin is different from the way it works in a mid-ocean spreading center. In back-arc basins, which are widespread in the western Pacific Ocean, a spre
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Contact: Barbara K. Kennedy
science@psu.edu
814-863-4682
Penn State
23-Sep-2004