Across
- 5. Tectonic plates meet and the edge of one plate descends below the edge of the other.
- 8. Process where the nucleus of an unstable atom loses energy by emitting radiation.
- 10. Waves of energy that travel through the Earth's layers.
- 13. Representation on a map of the natural and artificial features of an area.
- 15. Living factor
- 16. Processes that help build up the Earth.
- 18. An absences of oxygen
- 19. The true age of a rock or fossil.
- 20. The presence of oxygen
- 21. Branch of science studying earthquakes.
Down
- 1. The structure of Earth's crust and results of the rigid plates that move over the mantle.
- 2. Meteor that survives its passage through the Earth's atmosphere and hits the ground.
- 3. Dating rocks using the relative proportions of particular radioactive isotopes.
- 4. Movement in a fluid where hotter and less dense matter rises and colder and less dense matter sinks.
- 6. Time taken for the isotope to decrease into half its original value.
- 7. Determining the relative order of past events or objects.
- 9. Non-living factor
- 11. Different forms of the same element that have a different number of neutrons.
- 12. Process by which rock is broken down, such as erosion and weathering.
- 14. Close relationship of two factors that cause them to impact how each other change.
- 17. branch of science studying the magnetism in rocks.