The geosphere

The geosphere layers

• The crust. It ‘s the outer layer, made up of solid materials. Rocks.

The geosphere layers

• The mantle. It is the middle layer. It is extremely hot, up to 4000 º C. In some parts there are liquid rocks called magma.

The geosphere layers

• The core. It is the inner layer. It is also extremely hot, with temperatures up to 5000ºC-6000ºC.

• It is divided into two layers:– Outer core. Materials are liquid.– Inner core. Materials are solid because the high pressure and density.

Changes in the Geosphere

• Changes are produced in the geosphere by action of different geological agents:

- Inner agents: volcanoes, earthquakes, tectonic movements- Outer agents:

wind and water.

Volcanoes

• Volcanoes are formed in places where magma is under the surface.

• When a volcano erupts internal forces push magma up through a central pipe, the chimney or

vent.

Volcanoes

• Magma is called lava when it reaches the surface.

• This happens also with smoke, and ash through a circular opening called crater.

Volcanoes

• Layers of lava and ash cool and solidify around the crater and form a volcanic cone.

• Many islands were formed by underwater volcanic eruptions.

Earthquakes

• Earthquakes are caused by movements of the Earth’s crust.

• They can destroy buildings and bridges.• Earthquakes on the ocean floor produce enormous waves called tsunamis.

Weathering

• Weathering is the action of water and wind.• Erosion is the removal of soil and rocks by

wind and water.

Weathering

• Transport is the movement of eroded material, then these materials are accumulated in another place. This is sedimentation

or deposition.

Rocks

• Rocks are natural materials which make up the Earth’s crust.

• Rocks are made up of minerals. Minerals are pure materials we cannot break down into other substances.

Types of rock

• We can classify rocks into three types depending on how they are formed:- Sedimentary rocks are formed from pieces of other rocks or pieces of living things. Eg. Coal, gypsum.

Types of rock

• Igneous rocks are formed when magma cools and solidifies. Granite and basalt are igneous rocks.

Types of rock

• Metamorphic rocks are formed when heat or preassure changes the original rocks. Marble and slate are metamorphic rocks.

Types of rock

The landscape

• All the different features of the Earth’s surface make up the landscape.

I. Mountain landscapes

• In mountains landscapes we can find mountains and valleys.

• Mountains are raised parts of the Earth’s surface.• Valleys are low areas between mountains.• Rivers are often found in valleys.

Mountain landscapes

• Several mountains grouped together are called a mountain range.

• A long line of mountain ranges is called a mountain chain.

Altitude

• Altitude is the height of any point on the Earth’s surface above the sea level.

• In Spain the altitude refers to the sea level in Alicante.

II. Flat landscapes

• Flat landscapes or plains are large areas of flat land with no mountains or hills.

• A plateau is a plain at a high altitude.• La Mancha is a big plateau situated at about 600 meters above the sea level.

Flat landscapes

• Depressions are plains which are lower than the sorrounding land. Most of these depressions are covered by water.

Flat landscapes

• Coastal plains are flat land near the coast (the seaside).

III. Coastal landscapes

• The coast is the place where the land meets the sea.

• There are two types of coast:– Low-lying coast. Often with sandy beaches.– High coast. With mountains or high areas by the sea. Often with rocky cliffs.