Why are there ocean basins, continents, and mountains?

  • Exhibition Text

    • Over millions of years, ocean basins open and close, continents move and change shape, and mountains are pushed up and eroded away. Such dynamic processes continually reshape the surface of the Earth. The movement of rigid plates on the Earth’s surface, known as plate tectonics, is the cause of these changes. Volcanic eruptions and earthquakes are dramatic hints of the great movements that take place over the vastness of geological time.

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  • For Educators

    • Topic: Earth Science

      Subtopic: Earth Formation/Evolution

      Keywords: Earth (Planet)--Surface, Plate tectonics, Landforms, Geological time, Geology, Structural

      Audience: General

In This Section

Explosive volcanism

Explosive volcanism

Most explosive eruptions occur in volcanoes above subduction zones, where one tectonic plate dives beneath the other.

Non-explosive volcanism

Non-explosive volcanism

People associate volcanoes with spectacular explosive eruptions, yet most volcanoes erupt basalt, a fluid lava from the mantle that erupts effusively and forms flows. 

Earthquakes

Earthquakes

No other natural force compares in sheer power with earthquakes.

Mountain building

Mountain building

The mountain ranges that span the globe mark boundaries where the Earth’s plates converge.

Plate tectonics

Plate tectonics

Plate tectonics has emerged as one of the grand unifying theories of geology.