Earth s Landforms
Vocabulary Words theory continental drift fault magma lava weathering glacier erosion deposition delta
Theory: A possible explanation.
Continental drift: The continuing movement of the continental plates.
Fault: A crack in the Earth s crust along which movement happens.
Magma: Melted rock within the Earth.
Lava: Magma that has reached the Earth s surface.
Weathering: The wearing (washing) away of rock by air and water.
Glacier: A thick mass of slow moving ice.
Erosion: The carrying of land by forces of nature. (wind and water)
Deposition: The process of dropping sediment in a new location.
Delta: A triangular piece of land built from soil deposited at the mouth of a river.
Vocabulary Review 1. Continuous movement of tectonic plates. 2. Carrying away of land by wind and water. 3. A thick mass of slow moving ice. 4. The wearing of rock by air and water. 5. A possible explanation. 6. Process of dropping sediments in a new location. A. Deposition B. Theory C. Continental drift D. Glacier E. Weathering F. Erosion
What is the difference between lava and magma?
What are landforms? They are natural features or shapes of the earth.
LANDFORMS Volcanoes Mountains
LANDFORMS Hill Plateau
HOW ARE LANDFORMS FORMED?
An idea of how landforms came to be is the plate tectonics theory. The theory is that the Earth is made up of several large plates. As the plates move, they carry sections of the continent or ocean floors.
Scientists believe that the Earth was once one super continent known as Pangaea.
Scientists believe the movement of the continental plates caused the super continent to separate into the 7 continents.
The Earth is made up of FOUR (4) layers. 1. Crust 2. Mantle 3. Center 4. Inner Core
HOW ARE MOUNTAINS FORMED?
MOUNTAINS Mountains are formed in 2 ways: 1. When two plates push against each other and their edges crumple and fold. 2. When two plates collide and one moves up over the other.
MOUNTAINS The tectonic plates are always moving. They move really slowly. We don t feel the movement of the plates.
EARTHQUAKES Sometimes the tectonic plates shakes the earth s surface, this causes an earthquake.
EARTHQUAKES Earthquakes usually occur in areas along faults. Most faults cannot seen but some like the San Andreas Fault are visible.
SAN ANDREAS FAULT
1. What are landforms? 2. What are tectonic plates and how do they move? 3. What are the two ways mountains are created? 4. How are earthquakes created?
VOLCANOES Volcanoes are created when two tectonic plates push each other. The lower plates goes down into the Earth s mantle.
VOLCANOES When the rock melts, it produces a gas that mixes with magma. The openings of which lava flows are known as volcanoes.
VOLCANOES The lava from a volcano can build up to form a mountain. Paricutin Mountain
VOLCANOES Volcanoes come in different shapes and sizes. They can be coneshaped or wide and flat.
Volcanoes are classified into 3 sections, depending on how often they erupt.
ACTIVE VOLCANOES Active volcanoes are those that have continued to erupt since scientists have been keeping records.
DORMANT VOLCANOES Dormant volcanoes have been inactive for sometime but may possibly erupt again.
EXTINCT VOLCANOES Extinct volcanoes have no record of activity and are not expected to erupt again.
1. How do volcanoes happen? 2. How does a volcano create a mountain? 3. Discuss the 3 classification of volcanoes? 4. Why do you think scientists monitor volcanoes?
CHANGING THE EARTH S SURFACE Earth s surface can be changed in several ways.
CHANGING THE EARTH S SURFACE W- Weathering E- Erosion D- Deposition
WEATHERING Weathering is the washing away of rock. The two main causes of weathering are: wind and water.
SHIPTON S ARCH
WEATHERING The movement of glaciers can also change landforms. As the glaciers move, they grind the land below it, washing it away.
1. What is weathering? 2. What are the three causes of weathering?
EROSION After weathering washes away the rock, the land is carried away by wind and water. Erosion is the carrying away of the rock particles.
The tiny rock particles carried by wind, water and glaciers are called sediments.
DEPOSITION The dropping of sediments in a new location is called deposition.
Erosion wears away landforms and deposition builds new ones. Which do you think farmers would prefer and why?
What is the difference between erosion and deposition?
People Change the Land People can also change the land in several ways. 1. Turn landforms into farming areas. 2. Change land that would be difficult to use. 3. People build dams to produce electricity.
Growing rice on the Mountainside
People Change the Land 4. People also create human lakes to store water. 5. People drain water from wetlands to create lands for farming. 6. They direct water into dry areas.
List 3 ways people change the land.