Science Quiz

What the Earth appears to look like when viewed from outer space

A ball

Main layers of the Earth

Crust, mantle, core

The point where beyond direct observation of Earth’s interior is impossible

10 km deep

Outermost layer of Earth composed of continents and ocean basins

Crust

Thicker than the oceans

continental crust

Thinner than the continents

ocean crust

Continental crust thickness

35-70 km thick

Ocean crust thickness

5-10 km thick

Ocean crust

compact and composed of basalt

Continental crust

mainly composed of granite rock

Oxygen

Most abundant element in the crust

Crust

less than 2% of Earth’s radius

Mantle

about 2900 km thick, divided into upper and lower portions.

ferro-magnesium silicates

what the mantle is mainly composed of

plastic zone

allegedly where lava originates

Core

about 3500 km thick, divided into inner and outer layers; hottest part of the earth

Outer core

liquid iron and nickel, around 2300 km thick

Inner core

solid iron and nickel due to pressure, about 1200

6,000 - 10,000 degrees Celsius

Temperature in the core

Continental drift theory, tectonic plate theory

Two main theories on crustal movement

200 million years ago

Allegedly when continents broke into smaller forms

Alfred Wegener

A German geophysicist and meteorologist who proposed the continental drift theory in 1912