Across
- 2. a deep undersea valley where crust sinks towards the mantle
- 3. floor spreading the process by which molten material adds new crust below earth's bodies of water
- 4. apartment housing that is overcrowded and not well taken care of
- 7. a force that sends an object forward
- 8. the way a person behaves
Down
- 1. an original version of blueprint
- 3. a device that reflects sound waves off underwater objects and records the echoes
- 5. the process by which crust sinks back into the mantle at a colliding plate boundary
- 6. an aggressive young man that is usually a trouble maker
- 9. ocean ridge an undersea chain of mountains that is part of a long system of underwater mountains