What type of plate boundary creates a trench?

Question

:) thanks

Answer 1

Trench form at subduction zones i.e convergent boundary.They are the spectacular and distinctive morphological features of convergent plate boundaries.Plates move together along convergent plate boundaries at convergence rates that vary from a few millimeters to ten or more centimeters per year. A trench marks the position at which the flexed, subducting slab begins to descend beneath another lithospheric slab. Trenches are generally parallel to a volcanic island arc, and trenches about 200 km from a volcanic arc. Oceanic trenches typically extend 3 to 4 km (1.9 to 2.5 mi) below the level of the surrounding oceanic floor

Trenches are related to but distinguished from continental collision zones (like that between India and Asia to form the Himalaya), where continental crust enters the subduction zone. When buoyant continental crust enters a trench, subduction eventually stops and the convergent plate margin becomes a collision zone.

so we can say that Trenches form where oceanic lithosphere is subducted at a convergent plate margin, presently at a global rate of about a tenth of a square metre per second.

There are several factors that control the depth of trenches. The most important control is the supply of sediment, which fills the trench so that there is no bathymetric expression. It is therefore not surprising that the deepest trenches (deeper than 8,000 m) are all nonaccretionary. In contrast, all trenches with growing accretionary prisms are shallower than 8000 m. A second order control on trench depth is the age of the lithosphere at the time of subduction. Because oceanic lithosphere cools and thickens as it ages, it subsides. The older the seafloor, the deeper it lies and this determines a minimum depth from which seafloor begins its descent. This obvious correlation can be removed by looking at the relative depth, the difference between regional seafloor depth and maximum trench depth. Relative depth may be controlled by the age of the lithosphere at the trench, the convergence rate, and the dip of the subducted slab at intermediate depths. Finally, narrow slabs can sink and roll back more rapidly than broad plates, because it is easier for underlying asthenosphere to flow around the edges of the sinking plate. Such slabs may have steep dips at relatively shallow depths and so may be associated with unusually deep trenches, such as the Challenger Deep.

Answer 2

Trenches are formed at subduction zones. This is when one plate is being shoved under the other causing earthquakes, volcanic activity, mountain forming, and in some cases deep trenches such as the one you see in the Pacific Ocean running along the side of Japan.

Answer 3

Trenchs are formed at subduction zones along a Convergant boundary

Answer 4

A convergent or destructive boundary plate, forms an ocean trench, and also folds mountains.

Example: South American Plate and Nazca Plates (Forming the Andes and a deep sea trench, "Peru-Chile Trench")

Answer 5

subduction zones