It begins just like the worst examples of cover letters on the Internet: "TO WHOM IT MAY CONCERN." But the rest of it is pretty awesome. It turns out it's a note buried by Paul Walker, an American geologist well known to those in his field today. He built two rock "cairns" in this remote spot, as the discovering scientist, Warwick Vincent of Laval University in Quebec, described them. Walker asks scientists of the future to measure the distance between the two cairns, one of which is located on the Ward Hunt ice shelf. Walker wanted to know whether the ice shelf, the Artic's largest, was growing or retreating.