Sunda Trench an underwater ridge, and much of the trench is at least partially filled with sediments. Mappings after the 2004 Indian Ocean earthquake of the plate boundary showed resemblance to suspension bridge cables, with peaks and sags, indicative of asperity and locked faults, instead of the traditional wedge shape expected. Some of the earliest exploration of the Trench occurred in the late 1950s when Robert Fisher, Research Geologist at the Scripps Institution of Oceanography, investigated the trench as part of a worldwide scientific field exploration of the world's ocean floor and sub-oceanic crustal-structure. Bomb-sounding, echo-train analysis and manometer were some of
Mariana Trench poles than at the equator. As a result, parts of the Arctic Ocean seabed are at least closer to the Earth's centre than the Challenger Deep seafloor. In 2009, the Marianas Trench was established as a United States National Monument. Xenophyophores have been found in the trench by Scripps Institution of Oceanography researchers at a record depth of below the sea surface. On 17 March 2013, researchers from the Scottish Association for Marine Science reported data that suggested microbial life forms thrive within the trench. The Mariana Trench is named for the nearby Mariana Islands (in turn named Las Marianas