Across
- 2. the study of the solid earth and its layers
- 4. weather is part of this branch of earth science
- 6. the earth's layer directly under the crust
- 7. first determined the circumference of earth
- 10. caused by gravity and helped form the sun
- 12. added oxygen to the atmosphere
- 13. formed by gases erupting from volcanoes at earth's birth
- 15. evidence for the spherical nature of earth
Down
- 1. composed of solid iron and nickel
- 3. the mass per volume of a substance
- 5. the study of the ocean and its currents
- 8. condensed into water and accumulated as oceans
- 9. device used by astonomers to study space
- 11. outer most layer of the earth
- 14. not quite a perfect sphere