University of Wisconsin-River Falls

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Feb. 27, 2004


Distinguished Geochemist Lectures at UW-River Falls

A nationally prominent geochemist from the Woods Hole Oceanographic Institution will speak at UW-River Falls on March 8 about oceanic geysers and the chemical soup they produce at the ocean bottom.

Margaret Kingston Tivey, an associate scientist at the Institution, will lecture at 7:30 p.m. in Room 200 of the Agriculture Science Building. It is free and open to the public.

Tivey travels the world studying active seafloor vents using human occupied submersibles, such as the Alvin, the Nautile and the Turtle, and remotely operated vehicles, such as Jason, ROPOS and Tiburon.

Seafloor vents were discovered in 1977, when scientists found vents of warm mineral-rich fluids gushing from the ocean floor, according to Woods Hole. These are basically seafloor hot springs.

The surface of the earth is comprised of plates moving in opposite directions. In places where the plates are separating, columns of molten rock rise toward the Earth's surface. Lava then erupts and forms new oceanic crust, which in turn creates volcanic mountain ranges called mid-ocean ranges.

Hot rocks contract when they cool, producing cracks in the new seafloor. As seawater enters those cracks, it is heated and rises back through the ocean. These plumes are similar to geysers on land, and can rise 900 feet in the ocean.

Seafloor hydrothermal vents are located along the Earth's mid-ocean ridges at depths of one to two miles. The fluids that flow from the vents are acidic and rich in metal and sulfide. The mixing of these fluids and seawater results in the formation of metal deposits on the seafloor.

Studying sea vents is helping scientists to better understand many aspects of the earth's geological systems.

Tivey majored in geology at Stanford University. She was introduced to seafloor hydrothermal systems at the University of Washington, where she received her doctorate in 1988 and then went to work at Woods Hole.

Tivey is visiting UW-RF as part of a distinguished lecturer series sponsored by Ridge 2000, a consortium of universities studying the Earth's mid-ocean ridge system. The lecture is sponsored by the UW-RF department of plant and earth science and the National Science Foundation. UW-RF was selected as one of a handful of institutions in the country to host a speaker from the series.

For more information, contact geology Professor Bill Cordua at 715/425-3139 or william.s.cordua@uwrf.edu.

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