Download Internal Forces- Rapid Changes to the Earth

Internal Forces- Rapid Changes to the Earth
The earth’s features are always changing, and sometimes those changes
happen suddenly. Earth’s features may be referred to as Landforms.
Geologists, or people who study the earth’s structure and history, can tell
how old rocks are and the way different types of mountains were formed.
Landforms are ways to describe the surface of the earth in a particular area
of the earth. Some landforms are:
1. Plains- an area of land that is wide and flat.
2. Valleys- an area of land that is between mountains or hills.
This area is lower than the mountain or hill and has a V or U
shape, depending on how it is formed.
3. Hills- these are areas where the land is high (not as high as a
mountain) and the tops are usually rounded.
4. Mountains- Very high and steep areas of land.
Rapid Changes to the earth’s surface are caused by sudden events or events
that happen over short periods of time. Some of these events are:
Volcanic Eruptions- This is a sudden change to the earth’s
surface when pressure and heat below the earth’s surface build up, melted
rock and ash come rushing through an opening of the earth’s surface. When
the melted rock is out on the earth’s surface, it is called Lava. Lava flows
(sometimes miles away) and then it cools, reshaping the land in that
surrounding area.
Landslides- These occur very quickly. Usually, landslides are
due to lots of rain in the area. Rock and soil are loosened and move suddenly
down the side of the hill, pulled by gravity.
Earthquakes- happen when a part of the earth’s crust shakes
violently due to a build up of pressure within the earth. Earthquakes happen
along fault lines. This shaking and movement of the earth’s crust causes
changes of landforms. The movement at the fault lines may happen in
different ways:
1. Transform boundary-Land at fault may slip side by side
2. Divergent boundary-Land on either side of the fault may pull
away from each other- causing a crack at the earth’s surface.
3. Subduction-Land on one side of the fault may be pushed over
the other side- causing a cliff type effect.
4. Convergent Boundary- Plates may collide into each other.