Layers of the Earth
Earth's Atmosphere and Oceans
Evidence for Earth's Structure
Wild Card
100

The outermost layer of the Earth, composed primarily of light rocks containing elements such as silica and aluminum. 

What is the crust? 

100

The process of a liquid changing to a gas. 

What is evaporation?

100

A type of seismic wave that travels through both liquid and solid states of matter.

What is a P-wave (primary wave)?

100

An invisible field around Earth created by convection currents from the outer core that protect the surface of the Earth from solar winds and UV radiation. 

What is Earth's magnetic field? 

200

An extremely dense and hot layer of Earth made of almost pure iron; it remains solid due to it's extreme pressure. 

What is the inner core? 

200

Blue-green bacteria that photosynthesized; they produced enough O2 to change the chemistry of the atmosphere and oceans.

What are cyanobacteria?

200

A type of seismic wave that travels through solid states of matter only.

What is an s-wave (secondary wave)?

200

The relatively thicker part of Earth's crust that makes up landmasses. 

What is continental crust? 

300

The layer of Earth made primarily of liquid iron and nickel; the convection currents it creates is responsible for Earth's magnetic field. 

What is the outer core? 

300

An explosion of evolution (540-485 MYA) that led to much life and rapid diversification.

What is the Cambrian Explosion? 

300
Charged particles emitted from the sun that travel through space. 

What is solar wind? 

300

Material that moves from one area via water, wind, or other forces then settles in another area.

What is sediment? 

400

The thinner, denser part of Earth's crust that make up the oceans basins.

What is oceanic crust? 

400

A layer of O3 molecules in the atmosphere that prevent Earth's surface from experiencing harmful UV radiation levels.

What is the ozone? 

400

All the solid, non-living parts of Earth, including rocks, minerals, soil, and landmasses. 

What is the geosphere? 

400

Part of the upper mantle; this area is solid but moves like liquid, and tectonic plates move on top of it. 

What is the Asthenosphere? 

500

The layer of Earth that comprises 70% of its entire volume; it is solid and varies in density.

What is the Mantle? 

500

Many organisms (including cyanobacteria) use this process to to make food using sunlight, releasing oxygen as a byproduct.

What is photosynthesis? 

500

The process of planets separating into layers by density due to gravity, with heavy things sinking to the middle while lighter things stay towards the surface. 

What is differentiation? 

500

Earth's brittle outer shell; it contains the crust (both continental and oceanic layers) and the upper part of the mantle, all of which is very rocky. 

What is the lithosphere?