Across
- 1. a deep undersea valley were crust sinks towards the mantel
- 5. the process by which crust sinks bake into the mantel at a
- 6. bodies of water
- 8. ocean rig an undersea chain of mountains that is part of a long
- 9. a device that reflects sound waves off under objects and
Down
- 2. plat bondery
- 3. of underwater mountains
- 4. the echoes
- 7. floor spreading the process by which molten adds new crust bellow