The tropical Island of Guam in the Western Pacific is one of the Mariana Islands.

Politically it is US-Territory and it seems to be a nice island for tourists as well. But for geologists it is much more. It is the top of a giant vulcano rising up from the seafloor. Near to Guam is the Mariana trench, where the Pacific Plate, an immense part of the earth’s crust, converges with the Phillipine Plate. At this trench the seafloor reaches its maximum depth of all around the globe. In the surrounding of this subduction zone striking tectonic and geochemical events take place and form submarine vulcanoes and also mud-vulcanoes, which are little known to the world up here, because they do not appear above sea level.

So the scientists of IODP Expedition 366 will set out to explore this quite unknown part of submarine reality.