More than two -thirds of the earth's surface is covered by water , and especially the deep sea is still only poorly understood . What animals there are down there , what life is all possible in the extreme environment of submarine volcanoes and black smoke ? To find out, has Robert Ballard, an explorer in residence at the National Geographic Society , made several expeditions to the bottom of the ocean with submersibles and robots. Oceanographer became famous in 1985 by the Discovery of " Titanic." Now he examined with the latest technology tectonic zones off Hawaii and the Mediterranean , where , among other things the active volcano " Kolumbos " near the Aegean island of Santorini. His conclusion: " The one must keep in mind. "