Biology 210 with Walsh at Trident Technical College *. * The material on this site is created by StudyBlue users. StudyBlue is not affiliated with, sponsored by or endorsed by the academic institution or instructor.
Mid-ocean ridges (eg. Mid Atlantic Ridge) are formed at constructive plate boundaries, where magma is welling up between two diverging plates and forming new plate materiel. Trenches (eg. Marianas Trench) are formed at destructive plate boundaries where an ocean plate is being subducted below a continental plate.Chariotmender Â· 8 years ago.id Atlantic Ridge) are formed at constructive plate boundaries, where magma is welling up between two diverging plates and forming new plate materiel. Trenches (eg. Marianas Trench) are formed at destructive plate boundaries where an ocean plate is being subducted below a continental plate. Chariotmender Â· 8 years ago.
Oceanic crust is formed at an oceanic ridge, while the lithosphere is subducted back into the asthenosphere at trenches. The oceanic trenches are hemispheric-scale long but narrow topographic depressions of the sea floor. They are also the deepest parts of the ocean floor. Oceanic trenches are a distinctive morphological feature of convergent plate boundaries, along which lithospheric plates move towards each other at rates that vary from a few mm to over ten cm per year.