Early Earth
Earth's Layers 1
Earth's Layers 2
Earth's Layers 3
100

How were cyanobacteria involved in helping to create today's atmosphere?

They produced oxygen through photosynthesis.

100

Which of Earth's layers do we stand on?

Crust

100

What kind of crust do most tectonic plates contain: continental, oceanic, or both?

Both

100

Which of Earth's layers is the largest?

Mantle

200

How did the formation of the ozone layer allow for life to flourish on Earth?

It block harmful UV rays from the sun.

200

In which of Earth's layers does convection of magma occur to drive the movement of tectonic plates? (Be specific.)

Asthenosphere

200

Which state of matter is the mesosphere?

Solid

200

Describe how both temperature and pressure change as you go deeper into the Earth.

They both increase

300

How did Earth's first actual atmosphere disappear?

A Mars-sized body smashed into Earth, blowing it away.

300

Name Earth's structural layers in order of depth.

Lithosphere, asthenosphere, mesosphere, outer core, inner core

300

Parts of which two compositional layers form the lithosphere?

Crust and mantle

300

In terms of Earth's layers, describe differentiation.

Materials within Earth separate by density, with denser materials sinking to the core due to gravity.

400

Earth initially had a temporary, short-lived atmosphere before its first real one stuck around. What did this temporary atmosphere consist of, and how did it disappear?

a. Hydrogen and helium

b. Solar wind

400
Explain how scientists discovered that the outer core was liquid.
P waves from earthquakes move through everything, though S waves don't move through liquids, and scientists found that S waves weren't moving through that section of the planet, meaning that this "outer core" was liquid.
400

Describe the composition of the inner and outer cores (what they're made of) and whether they are solid or liquid.

Outer core: Liquid; iron and nickel

Inner core: Solid, iron and nickel

400

Describe two facts about the asthenosphere.

-Solid (though putty-like/plastic)

-Part of the mantle/under the lithosphere

-It is where convection happens that moves the tectonic plates

-Etc.

500

a. Look at the following graph. What were the component gasses of Earth's first actual atmosphere?

b. Where did these gasses come from?

a. Water vapor, carbon dioxide, nitrogen, methane and ammonia

b. Volcanoes

500

What is convection, and how does it work?

Convection is cyclical heat transfer through a fluid --> When the fluid heats up, it spreads apart to become less dense, causing it to rise. When it cools away from the heat source, it condenses more, causing it to sink. This creates a self-sustaining cycle.

500

a. Describe what is always occurring on the ocean floor with lithosphere.

b. Which type of crust has higher concentrations of magnesium and iron, oceanic or continental?

a. It is being formed at mid-ocean ridges, moves outward, and gets recycled back into the mantle at trenches.

b. Oceanic

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