Earth and Space Vocabularies

1. The splitting apart of a single tectonic plate into two or more tectonic plates.
5. The mechanically weak region of the upper mantle of Earth.
6. The force exerted on a surface by the air above it as gravity pulls it to Earth.
8. The relatively thick part of the earth's crust that forms the large landmasses.
10. The region of the earth's atmosphere above the stratosphere and below the thermosphere, between about 30 and 50 miles (50 and 80 km) in altitude.
11. The boundary between the crust and the mantle in the earth.
13. A natural substance composed of solid crystals of different minerals that have been fused together into a solid lump.
15. The degree of hotness or coldness of the atmosphere on some chosen scale.
18. The outermost layer.
19. The mostly-solid bulk of Earth's interior.
20. The hot solid material with high pressure found in the centre.

2. A current in a fluid that results from convection.
3. The relatively thin part of the earth's crust which underlies the ocean basins.
4. A supercontinent that incorporated almost all the landmasses on Earth.
7. Relating to an earth vibration caused by something else.
9. Massive slab of solid rock made up of Earth's lithosphere
12. The part that is responsible for generating the planet's magnetic field.
14. The rigid, outermost rocky shell of our planet.
16. A measure of mass per unit of volume.
17. An object that's reduced to liquid form by heating.