Geography of Indonesia is responsible for the creation of the Sunda Trench, and mountain ranges across Sumatra, Java, and the Lesser Sunda Islands. Many great earthquakes occurred in the vicinity of the fault, such as the 2004 Indian Ocean earthquake. Mount Merapi, located in the Java portion of the megathrust, is the most active volcano in Indonesia and is designated as one of world's Decade Volcanoes due to the hazard it poses to the surrounding populated areas. The northern part of Sulawesi and Maluku Islands lie on the convergence of Sunda Plate and Molucca Sea Plate, making it an active tectonic region with
Philippine Trench a M 8.2. The trench reaches one of the greatest depths in the ocean, third only to the Mariana trench and the Tonga trench. Its deepest point is known as Galathea Depth and reaches 10,540 meters (34,580 ft) or (5,760 fathoms). Sedimentation of the Philippine trench contains slightly metamorphosed, calc-alkalic, basic, ultrabasic rock and sand grains. The southern area of the trench contains homogenous, blue, clay silt and was poor in lime. Sand grains that were also found contained fresh basaltic andesite. The sediments found in the trenches are hypothesized to have been deposited by turbidity currents. A turbidity current