Answer:
1. They are deeper than the typical abyssal plane, usually greater than 20,000 feet.
2. Arc-shapped.
3. Adjacent to an arc-shapped chain of volcanic islands or adjacent to a chain of active volcanoes on larger land mass (example Japan Trench next to Japanese islands with active volcanoes)..
4. Deep focus earthquakes.
5. Thrust faulting on hanging wall of (upper plate that is not being subducted).
6. Oldest sediments on the subducting plate are closer to the trench.
Explanation:
