Tectonic Plates

2. A scientific theory that explains how major landforms are created due to Earth's subterranean movements.
6. Vibrations in the earth that transmit energy and occur during earthquakes.
7. The study of the forms and features of land surfaces.
10. Forces that build up an existing landform or create a new one.
11. Form where a plate with thinner oceanic crust descends beneath a plate with thicker continental crust.
13. When a meteoroid survives a trip through the atmosphere and hits the ground.
14. Calculates an age in years for geologic materials by measuring the presence of a short-life radioactive element.
17. The emission of energy in the form of ionizing radiation.
19. The age of a natural material in years.
20. A Coherent domain of Earth's continental crust that has attained and maintained long-term stability.
21. A massive, irregularly shaped slab of solid rock.

1. A branch of science concerned with earthquakes and related phenomena.
3. Formed where two tectonic plates pass laterally by one another.
4. Occurs when two tectonic plates move away from each other.
5. Distinct nuclear species of the same chemical element.
8. Modify or even destroy landforms.
9. The study of prehistoric Earth's magnetic fields recorded in rocks, sediment, or archeological materials.
12. The mass movement of a material due to density differences caused by a variation in either composition or temperature.
15. The process of determining if one rock or geologic event is older or younger than another, without knowing their specific ages.
16. The time required for one-half of the radioactive parent isotopes in a sample to decay to radiogenic daughter isotopes.
18. When two plates come together.