(3)During a recent (2003) research expedition to Gakkel ridge, a chain of volcanic mountains submerged in the Arctic Ocean, German and American scientists discovered surprisingly strong hydrothermal activity. The researchers had expected to find the ridge "hydrothermally dead," however instrument readings from the area showed much activity, including an active hot spring on the ocean floor. Robert Felix(1) believes such underwater volcanic activity is heating the seas and instigating climate change.
For more info read The Fiery Face of the Arctic Deep(2).
Photo of ice breaker and research ships: Henry Dick, Woods Hole Oceanographic Institution/NSF.