Key Concepts in Physical Geography

Earth's Continents and Oceans

The continents are large landmasses on Earth's surface. The main continents are:

• Asia
• North America
• South America
• Europe
• Oceania
• Africa
• Antarctica

Oceans are large bodies of salt water. The major oceans are:

• Pacific Ocean
• Indian Ocean
• Atlantic Ocean
• Arctic Ocean

Major Landforms

The land surface is neither smooth nor uniform. Various landforms shape the terrain.

Mountains

High elevations of terrain. If a grouping is of little extension, it constitutes a range, and if it is of great extension, a cordillera.

Plains

Large tracts of land that are flat or slightly wavy.

Plateaus

Large areas of land with a flat upper surface, often elevated.

Valleys

Sunken areas of land, often elongated, surrounded by highlands.

River Systems and Features

Flow Rate

The amount of water flowing through the channel of a river.

Stream

A small body of flowing water, often with low flow and intermittent.

River Valleys

Valleys created by a river, often having a "V" shape in their upper course.

Gullies

When river valleys are very narrow, deep, and have steep walls, often found in mountainous terrain.

A river can be divided into three main sections:

• Headwaters

  Comprises the birth of the river and its first stages; this is the steepest area.

• Middle Course

  The ground has less slope. The waters of the river flow more slowly.

• Lower Course

  It is the final stretch of the river that ends at its mouth.

Delta

A landform created by the accumulation of materials deposited at the river mouth.

Estuary

A funnel-shaped river mouth open to the sea coast, often originating in areas with strong tides.

Other Water Bodies

Glaciers

Large masses of ice formed in the highlands of cordilleras.

Groundwater

Originates from the filtration of rainwater, rivers, or streams through permeable and porous rocks.

Lakes and Inland Seas

A lake is a permanent accumulation of water in a sunken area. It is called a lagoon when its size is smaller and an inland sea when its extension is great and its water is salty.

Coastal Features

Beaches

Originate on low-lying coasts due to material accumulation.

Cliffs

High, steep coastal landforms.

Gulfs

Large inlets of the sea into the land.

Capes

Parts of the coast that project out into the sea.

Volcanic Activity and Features

Volcanic Eruptions

Consist of material from the Earth's interior, such as molten rock (lava), gases, and ash, being expelled onto the surface.

Crater

The top of a volcano, often funnel-shaped, through which lava, gas, and other materials are expelled.

Volcanic Cone

The accumulation of ejected material around the volcanic vent, forming the mountain shape.

Vent

A passage within a volcano through which its interior communicates with the crater.

Earthquakes and Seismic Terms

Earthquakes

Tremors or shaking of the ground caused by sudden movements within the Earth's interior.

Hypocenter

The point inside the Earth where an earthquake originates and where seismic waves are formed.

Seismic Waves

Waves of energy that propagate the tremor of an earthquake through the Earth.

Epicenter

The point on the Earth's surface directly above the hypocenter, where the shaking of an earthquake is typically most intense.