History of Earth

1. Time Scale A system used by geologists to describe the timing and relationships of events in Earth's history.
4. The rigid outer layer of the Earth, including the crust and upper mantle.
5. A crack in the Earth's crust where blocks of rock have moved past each other.
9. A subdivision of an era on the geologic time scale, lasting millions of years.
10. Related to earthquakes or the vibrations caused by them.
13. An opening in the Earth's crust through which molten rock, ash, and gases can escape.
14. Drift The theory that continents move over time due to tectonic activity.

2. A sudden shaking of the ground caused by the movement of tectonic plates.
3. Record The history of life on Earth as documented by fossils, which provides evidence of past organisms and their environments.
6. The study of the Earth's structure and the movement of its plates.
7. A division of geological time that is smaller than an eon and can last tens to hundreds of millions of years.
8. The process where one tectonic plate moves under another plate and sinks into the mantle.
9. A large slab of solid rock that makes up the Earth's surface.
11. The largest division of geological time, spanning hundreds of millions to billions of years.
12. The layer of the Earth located between the crust and the core; it is semi-solid and drives plate movement.