1.4 Earth Conveyer Belt

Question 1

Earth’s Internal Structure

Answer 1

The Earth’s outer liquid core flows and swirls to generate our magnetic field, most of it’s heat is generated within the mantle through radioactive decay, it’s primarily composed of Periodtite. The Earth’s temperature comes closest to the melting temperature for Peridotite at the asthenosphere (the upper layer of the earth’s mantle) which is generally a weak zone.

Question 2

Ridge Push/Slab Pull

Answer 2

The driving force of plate tectonics. Mid-ocean ridges push away under gravity, as they’re being pulled at the other end by gravity fed subduction.

Question 3

Mantle Convection

Answer 3

When the mantle is heated from the core and in the hotter areas it rises upwards, and in cooler areas it sinks down, resulting min convection cells in the mantle and producing horizontal motion of mantle material close the Earth’s surface.

Question 4

Paleomagnetism

Answer 4

The study of past changes in the Earth’s magnetic field, which reverses ever 200,000 years, magnetic minerals in cooling lava record the information.

Question 5

The Earth’s Structure

Answer 5

Inner core
Outer Core
Mantle/Asthenosphere
Crust/Lithosphere

Question 6

Inner Core

Answer 6

Heat from inner core convects through the mantle into the asthenosphere, it’s in the solid state because of the mad pressures.

Question 7

Outer Core

Answer 7

Hot magma is less dense than cooler magma and therefore rises.

Question 8

Mantle/Asthenosphere

Answer 8

Magma is cooler at the top as it’s further away from the core which is the magma’s heat source.

Question 9

Crust/Lithosphere

Answer 9

The crust is the most outer layer and the thinnest, least dense and lightest.

Question 10

What Happens When The Earth Cools

Answer 10

The inner core grows roughly by a mm every year because of magma solidifying, it grows in lumps because of the activity happening in the surrounding mantle. Growth is more concentrated around subduction zones, because plates draw heat from the core causing more cooling.

Question 11

Mid-Ocean Ridge

Answer 11

Ridge push is where a slope is created when plates move apart and gravity is acting upon it is at a higher elevation, gravity makes the gap wider, they’re also being pulled at the other end due to subduction.

Question 12

Seafloor Spreading

Answer 12

New land forming on the ocean floor by lava filling the gaps.