Moulin Bleu

Greenland is melting and its ice sheet moving oceanward at an accelerating pace, but how? The mechanics of the meltdown were explicated in a 2002 paper that showed how increasingly abundant surface meltwater travels through large tunnels called moulins to the base of the 3/4-mile-thick ice sheet, providing a lubricating layer which helps speed the mass toward the coast. As the ice flows and melts it also thins, lowering the surface elevation -- all of which could contribute to a feedback loop that would reinforce melting.