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Smoke Stack

A mechanical arm on the Alvin submersible reaches out for a sample from a “black smoker” hydrothermal vent along the East Pacific Rise. Black smokers are so named because they can appear as if dark smoke is billowing from them. In fact, the “smoke” is actually iron- and sulfur-rich minerals precipitating from scalding vent waters as hot as 760°F meet the icy cold depths. (Photo courtesy of Woods Hole Oceanographic Institution Archives)