b'Over the past several months, scientists working in Antarctica have been watching\\u2014with a mixture of professional fascination and personal horror\\u2014a fissure growing in the continent\\u2019s fourth-largest ice shelf. Since last November, the crack has lengthened by some 90 miles. It has 13 miles more before it rends completely, and a chunk of ice the size of Delaware goes bobbing into the Weddell Sea.\\nLearn more about your ad choices. Visit podcastchoices.com/adchoices'