Reuters: A yellow submarine has helped to solve a puzzle about one of Antarctica’s fastest-melting glaciers, adding to concerns about how climate change may push up world sea levels, scientists said Sunday. The robot submarine, deployed under the ice shelf floating on the sea at the end of the Pine Island Glacier, found that the ice was no longer resting on a subsea ridge that had slowed the glacier’s slide until the early 1970s. Antarctica is key to predicting the rise in sea levels …