There are many ways scientists can gather evidence to learn about Earth's interior including direct evidence from rock samples and indirect evidence from seismic waves.
How far can we dig to the center of the Earth?
Video Guide:
|
|
So if we can't dig and "see" past the crust... how do we know what is inside Earth?
Evidence #1 - Volcanic Eruptions
Volcanoes both fascinate and frighten people because of the beautiful landforms they create and the powerful force of volcanic eruptions. Studies of rock, minerals, and gas erupted from volcanoes provide valuable clues about what is in the Earth’s interior.
Video Guide:
|
|
Evidence #2 - Principles of Density
Earth's interior layers are ordered by density. The densest layer is the solid metal inner core, the mantle is of intermediate density, and the least dense layer is the crust. This is because the force of gravity pulls more strongly on denser materials so denser materials are at the center of things including the Solar System!
|
Video Guide:
|
|
Evidence #3 - Earth is Magnetic
The Earth's invisible magnetic field extends from the Earth's interior way out into space and is believed to be generated by the liquid and solid iron alloys in Earth's core. Earth's magnetic field is an extremely complex process however, the fact that Earth creates a magnetic field provides important clues to what is deep inside Earth. Extremely dense moving metals.
|
More "Groundbreaking" Evidence Coming Up Next!
Seismic waves created from earthquakes pass throughout Earth's interior. These waves reveal vital information about the internal structure of the Earth that we will explore next!
Topic Tips
- Scientists must use direct and indirect evidence to infer what is deep inside Earth. Some of that evidence includes material erupted from volcanoes, principles of density, and Earth's magnetic field.