Earth's Layers and Formation Outline

Vocabulary flashcards covering Earth's shape, its four major systems, and the solar nebula formation process.

Oblate Spheroid

The true shape of Earth, which is not quite spherical.

Hydrosphere

The Earth system containing water on Earth's surface and underground, including rain, snow, and bodies of water (most of which is saltwater).

Atmosphere

The outermost layer of Earth made of surrounding gases, consisting of a mixture of nitrogen, oxygen, carbon dioxide, and traces of other gases.

Geosphere

Earth's entire solid body, including a thin layer of soil and sediment covering a big rock center.

Biosphere

The Earth system of living organisms that live within and interact with the atmosphere, hydrosphere, and geosphere.

Cryosphere

The component of Earth's water systems consisting of frozen water.

Gravity

The force via which Earth formed, which depends on the mass of objects and the distance between two objects.

Solar Nebula

A spherical cloud pulled together from a supernova by gravity, which rotates and flattens into a disk as gases are pulled closer together.

Accretion

The process on the outer edge of the rotating disk where collisions caused early planets to form.

Elliptical Orbits

The oval-shaped (not circular) orbital paths in which modern planets travel around the sun.

What is the crust?

Earth's outermost, solid, rigid, least dense layer.

What elements make up the crust?

Oxygen (O) and Silicon (Si).

What are the two types of crust?

Continental (thick, less dense) and Oceanic (thin, dense).

What is the mantle?

Layer between the crust and outer core where convection occurs.

What elements make up the mantle?

Silicon (Si), Magnesium (Mg), and Iron (Fe).

What is convection?

The slow movement of molten rock that transfers heat.

What is the core?

Earth's center; hottest and densest layer.

What elements make up the core?

Iron (Fe) and Nickel (Ni).

What is the lithosphere?

Rigid outer layer made of the crust and top of the mantle.

What are tectonic plates made of?

The lithosphere.

What is the asthenosphere?

Upper mantle with plastic-like rock that flows.

How does the asthenosphere affect tectonic plates?

Its flowing rock helps move tectonic plates.

What is the mesosphere?

Lower mantle beneath the asthenosphere; solid rock that flows very slowly.

What is the outer core?

Liquid layer of iron and nickel beneath the mesosphere.

What elements make up the outer core?

Iron (Fe) and Nickel (Ni).

What creates Earth's magnetic field?

Movement of liquid iron and nickel in the outer core.

What is the inner core?

Solid, extremely hot layer at Earth's center.

What elements make up the inner core?

Iron (Fe) and Nickel (Ni).

Why is the inner core solid despite being so hot?

Extreme pressure keeps the metals solid.

Which core layer is liquid?

Outer core.

Which core layer is solid?

Inner core.

Which Earth layer is hottest and densest?

The core.

Magnetosphere

Earth's magnetic bubble that protects it from harmful particles from space.

Landforms

Natural features of Earth's surface, like mountains and valleys.

Topography

The shape and features of an area of land.

Elevation

How high land is above sea level.

Relief

The difference in height between areas of land.

High relief

A large difference in elevation.

Low relief

A small difference in elevation.

Mountains

High elevation and high relief.

Plateaus

High elevation and generally low relief.

Earth's surface

About 70% is covered by water, mostly saltwater.

Cosmic rays

High-energy particles from space.