The amount of ice flowing into the sea from large glaciers in southern Greenland has almost doubled in the last 10 years, possibly requiring scientists to increase estimates of how much the world’s oceans could rise under the influence of global warming, according to a study being published today in the journal Science. The study said there was evidence that the rise in flows would soon spread to glaciers farther north in Greenland, which is covered with an ancient ice sheet nearly two miles thick in places, and which holds enough water to raise global sea levels 20 feet or more should it all flow into the ocean. The study compared various satellite measurements of the creeping ice in 1996, 2000 and 2005, and was done by researchers at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., and the University of Kansas. Glaciers are creeping rivers of ice that accelerate or slow and grow thicker or shrink depending on the interplay of a variety of conditions including rates of snowfall and temperature and whether water lubricates the interface between ice and the rock below. Sometimes the rate of movement in a particular glacier can change abruptly, but […]