Earth & Space Science - Structure Of The Earth

Front 1

Earth's Structure

Back 1

Almost spherical, flattened at the poles, & bulging at the equator. It is composed of 3 main layers: crust, mantle, & the core.

Front 2

CRUST

Back 2

•Earth's outer layer; it's solid crust is made up of GRANITE, BASALT, GABBRO, and other types of rock.

•Under the oceans, the crust is 3-6.8 miles thick; Under the continents the crust is from 12-40 miles thick.

Front 3

MANTLE

Back 3

•Earth's second layer; consists of silica & metal rich minerals.
•1,800 miles

Front 4

CORE

Back 4

•Has 2 layers; OUTER CORE, which is mostly liquid iron, and the INNER CORE, which is mostly solid iron.
•Extreme heat & pressure characterize the core.
•Outer core is 1,400 miles; Inner core is 810 miles.

Front 5

THEORY OF PLATE TECTONICS

Back 5

•Explains how seafloor spreads, major land forms are created and the continents move.
According to this theory, Earth's crust is made up of tectonic plates that fit together like a jigsaw puzzle.

•The plates move up to 6 inches a years.

•At the boundaries between plates, landforms such as mountains, volcanos, earthquakes, ocean trenches, and mid-ocean ridges occur.

Front 6

There are 3 types of plate boundaries, or margins...

Back 6

•Constructive Margin: 2 plates moving apart and creating new crusts. Molten material from the mantle below wells up in space between the plates, hardens, and forms new crust, usually at a mid-ocean ridge.

•Destructive Margin: when 2 plates collide & crust is destroyed. When a continental plate collides with oceanic plate, the denser oceanic plate is forced under, forming a deep trench.
When 2 continental plates collide with one another, crust crumbles & mountain ranges form.

•Conservative Margin(Transform): when 2 plates slide with one another & no crust is created or destroyed. Causes earthquakes.

Front 7

PANGEA

Back 7

•Plates carry continents with them.

•Scientists believe that a single large continent existed about 250 million years ago, called PANGEA. It gradually broke apart over millions of years, in which are now today's 7 continents.