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
Oceanic trench to dispose of sediment. An evolution in trench morphology can be expected, as oceans close and continents converge. While the ocean is wide, the trench may be far from continental sources of sediment and so may be deep. As continents approach each other, the trench can fill with continental sediments and become shallower. A simple way to approximate when the transition from subduction to collision has occurred is when the plate boundary previously marked by a trench is filled enough to rise above sea level. Accretionary prisms grow in two ways: by frontal accretion, whereby sediments are scraped off the