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The scientists uncovered what they are calling "seafloor storms" 10,000 feet dee

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  • Jon Liefs
    http://www.foxnews.com/scitech/110100/storms_fox.sml While most people equate the ocean depths with peacefulness, scientists have discovered masses of water in
    Message 1 of 1 , Nov 17, 2000
      http://www.foxnews.com/scitech/110100/storms_fox.sml

      While most people equate the ocean depths with peacefulness,
      scientists have discovered masses of water in motion thousands of
      feet down.

      AP/Wide World

      Rough storms like the one savaging this Swedish passenger ferry in
      1999 have been found to occur deep underwater.

      The scientists uncovered what they are calling "seafloor storms"
      10,000 feet deep in the Gulf of Mexico. These storms are powerful
      enough to carve furrows into the seafloor and whisk away animals and
      vegetation.

      The researchers are working to determine what causes the storms and
      what implications they might have.

      For example, the presence of these storms raises concerns for the
      builders of oil and gas wells in the region, said Ian MacDonald of
      Texas A&M University.

      The storms were discovered while researchers were conducting dives in
      the deep-sea submersible Alvin. Scientists had suspected their
      existence but had never confirmed them, MacDonald said.

      Unlike wind storms on land, the water movement was horizontal, not up
      and down, he said. The mass of moving water was 2,000 feet thick and
      the storm lasted for the length of a six-hour dive, he said. "We got
      to witness that first-hand."

      When researchers descended into a region about 180 miles south of the
      Louisiana coast, the submersible was caught in the current.

      "The sediments were stirred up by it. They saw fish and shrimp being
      whipped along like in a river ... animal life was being swept away,"
      MacDonald said.

      "That's an enormous force," he said.

      He added that the water movement in the area where the storm was
      viewed had channeled the seafloor into miles-long gullies. Previous
      readings from sonar had caused the scientists to suspect the storms
      occurred.

      The gullies "reminded me of the buttes and mesas in the Southwest,"
      he said.

      Along the edge of the continental shelf, where the sea floor plunges
      to depths of 8,000 to 10,000 feet, the masses of water researchers
      encountered were nearly 2,000 feet thick and moving at 1 to 1.5
      knots, MacDonald said. A knot is 1.15 miles per hour.

      While that sounds slow, normal water movement in the deep oceans is
      less than one-tenth of a knot. This relatively fast-moving water
      presses against anything in its path with a great force.

      William R. Bryant, a Texas A&M geologic oceanographer, was aboard
      Alvin during one dive into what he preferred to call a powerful
      current rather than a storm.

      But, he confirmed, "it was first time anyone had ever been in" one of
      these events.

      Currents had been measured by instruments before and the powerful
      ones were suspected because of the shape of the seafloor, said
      Bryant, who was swept along in a 1.5 knot current and believes some
      reach more than 2.5 knots.

      "Those are exceptional, high currents," he said. "We see large
      geological features, furrows, that are the result of these currents."

      Bryant said the currents are a "constraint" rather than a hazard to
      oil and gas rigs.

      The current is sufficient to undermine pipelines on the seafloor, he
      said, so oil and gas developers will have to determine the maximum
      speed of likely currents and create designs to cope with them.

      The expedition, which departed from Galveston, Texas on Oct. 16, was
      Alvin's first to the Gulf in eight years. It is operated by Woods
      Hole Oceanographic Institution.

      The National Oceanic and Atmospheric Administration sponsored the
      expedition through its National Undersea Research Program Center at
      the University of North Carolina at Wilmington.

      Besides Texas A&M, other organizations participating included
      Louisiana State University, University of South Carolina, College of
      William and Mary and the Department of Energy
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