GEOLOGY

Detailed explanation-1: -deep ocean trench-a deep valley along the ocean floor through which oceanic crust slowly sink toward the mantle. rift valley-a deep valley that forms where two plates move apart.

Detailed explanation-2: -Ocean trenches are long, narrow depressions on the seafloor. These chasms are the deepest parts of the ocean-and some of the deepest natural spots on Earth.

Detailed explanation-3: -Subduction happens where tectonic plates crash into each other instead of spreading apart. At subduction zones, the edge of the denser plate subducts, or slides, beneath the less-dense one. The denser lithospheric material then melts back into the Earth’s mantle.

Detailed explanation-4: -Ocean trenches are steep depressions in the deepest parts of the ocean [where old ocean crust from one tectonic plate is pushed beneath another plate, raising mountains, causing earthquakes, and forming volcanoes on the seafloor and on land.

Detailed explanation-5: -The Mariana Trench is part of the Izu–Bonin–Mariana subduction system that forms the boundary between two tectonic plates. In this system, the western edge of one plate, the Pacific Plate, is subducted (i.e., thrust) beneath the smaller Mariana Plate that lies to the west.