The Gregorian calendar

Developed nearly 500 years ago, it is a variant of the Julian calendar. Today it is the most widely used calendar.

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Wind at the beach

Sea and land breeze form because of the differing warming of land and sea.

Layers of the ocean

Physical properties, as well as the flora and fauna of the ocean change with depth.

The process of physical and chemical weathering

Upon physical weathering the rock only falls into pieces, whereas during chemical...

Volcanic activity

This animation demonstrates different types of volcanic eruptions

The desert

One third of the continents is covered with desert. Today, desertification is a...

Aeolian landforms on coasts and steppes

Wind, as an external force, plays an important role in shaping coastal areas and steppes.


An earthquake is one of the most devastating natural phenomena.

Weather fronts

When masses of cold and warm air meet, weather fronts develop.

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