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
Capture of Regina Trench army division), which had been brought from the Belgian coast. On 8 October, attacks by the 1st Canadian Division and the 3rd Canadian Division on Regina Trench, also failed. On 21 October, the 4th Canadian Division attacked the western portion of Regina Trench, as the 18th Division, 25th Division and the 39th Division of II Corps, attacked the part further west (known as Stuff Trench to the British). The Canadians met little opposition and gained the objective, as the II Corps divisions captured Stuff Trench in thirty minutes, giving the British control of the Thiepval Ridge. Three counter-attacks were repulsed