How Land Can Change

How the Land Can Change 

Section 1 - Introduction

The many different ways land can change.

There are many ways that land can change.

Land can be changed by wind, volcanic activity, water in its different forms, as well as by man.  

Land is changed by Wind

Wind can change the Land

Landforms can be shaped by natural forces like the wind.  When rock is broken apart by weathering, and pieces are carried away we call this erosion.  Most wind erosion occurs in desert areas where there is little water, few plants to block the wind, and there is a lack of roots to hold the soil down. 

Land is changed by volcanic activity

The land can be changed by Volcanic Activity

Volcanoes can cause changes to the Earth's landscape.  Volcanoes contain magma which is molten rock.  Gases in the magma create pressure that forces it to the surface through a central vent that leads to the top of the volcano.  When the magma reaches the volcano's top it will erupt.  Sometimes magma erupts through the top and other times through a side vent.  When the magma reaches the surface it is called lava.  The lava flows down the volcano sometimes reaching the ocean.  This lava will eventually cool and become part of the land, sometimes building on top of itself.

Land is changed by Water

Land can be changed by Water

Many landforms are shaped by moving water.  Sand and small rocks carried in rivers wear away the land.  The materials that are worn off get carried away.  Weathering is a process that breaks down rocks on the Earth's surface into smaller and smaller pieces. Water can change the land through weathering by removing or adding to the existing land.  Another way water changes the land is when it freezes into ice and expands.  This expanding can cause rocks to split apart.  

Glaciers, which are huge masses of ice and snow, can cause changes in the land.  When the glacier begins to melt it moves scraping the land beneath it and removing dirt and rock.  Then the glacier deposits the dirt and rock in other locations.

Land is changed by Man

Land can be changed by Man

There are many places we can see how people have changed the land by adding to or taking away from it.  There are places where man has dug down into the earth and built structures.  A dam is a man made structure that is built on a water system.  The water is blocked preventing it to flow freely and causing it to pool behind the dam.  When the water does this it can flood land that was previously  dry.  The flooded land which was habitat for certain animals is now changed.  Over time water is released from behind the dam which will lower the level of the water behind the dam.                                                                                                                                                                                

What type of erosion is this an example of?

  • Wind erosion
  • Water erosion

A process that breaks down rocks on the Earth's surface into smaller and smaller pieces is called what?

  • erosion
  • weathering
  • magma
  • erupting

A  ____________________ is a man made structure that is built on a water system.

Most wind erosion occurs in ______________ areas

  • Most wind erosion occurs in mountain areas.
  • Most wind erosion occurs in desert areas.

Volcanoes contain _______________ which is molten rock.

  • lava
  • magma
  • soil
  • gas

Which image shows an example of land being changed by water?

Explain in your own words using what we have studied, two different ways in which the land can change?