Update on the race to despoil the Arctic: This week, U.S. Coast Guard researchers set out on their third venture since 2003 to map the mineral-rich Arctic seafloor. There’s a lot to be learned about the watery depths; overall, maps of Mars are about 250 times better than maps of the ocean floor. The U.S. is eager to identify underwater mountains and caverns so we’ll know just where to stick our drills when global warming finally gets to doing something useful for a change: if current trends continue, the Arctic could be ice-free in summer by 2040. Russia, Denmark, Norway, and Canada are also maneuvering to get their hands on what one U.S. marine geologist calls “potential riches beyond your imagination.”

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