How is deep ocean trench formed?

Answer 1

• The above answers are correct, but gauging from the wording of your question, I might be able to word it better for you.

'Subduction Zone' means 'below the seafloor area'. Thats an ocena trench.

'Plate Techtonics' is a term that talks about 'plates' (exactly like your kitchen plate - that where the term comes from) that are where all the land is, all over the earth. The top layer is broken up like a puzzle. Each big puzzle piece is called a 'plate'. "Plate Techtonics" just explains how they interact. Things like volcanos in between each, earthquakes when they shift, and they do, and mountain ranges where they overlap each other is what Plate Techtonics explain. Earth's kitchen is messed up!

Deep Ocean trenches are formed in several ways. When the already formed earth was pulled by the moons or suns gravity too much over time (a lot), two plates may be pulled apart, and maybe a trench would form. Maybe in the ocean. Or underneath where a trench might be is where erosion, the eating away of the dirt by water action (there are currents underwater - right? -, and even under the bottom of the ocean, not all over, but some places) could 'eat away' the dirt below that part of the ocean floor, it would collapse, and a trench would form.

Or, even possibly, but I think unlikely, a water current along the ocena floor could 'dig' the trench, but most known ocean trenches are huge, and this would not be so well known. They are pretty dee, too. Don't let someone tell you one thing, if you think you may really know the answer. But be sure, proove it, too. Ask several friends, people and make your own realistic answer, within reason!

DMS, doveshawk.