1. Mariana Trench is the deepest oceanic trench on Earth. It is located in the western Pacific Ocean near the Mariana Islands, and it's formed as the Pacific Plate is subducted under the Mariana Plate. a. How are the Mariana Plate and Pacific Plate moving relative to each other? How do you know?

a. Mariana Plate and Pacific Plate are moving towards each other, with the Pacific Plate subducting (going under) the Mariana Plate. We know this because the passage states that the Mariana Trench is formed as the Pacific Plate is subducted under the Mariana Plate. Subduction implies a convergent boundary where plates are colliding and one is forced beneath the other.