1. Big Idea: Physical processes of the earth interact to form landforms.
Get out a piece of paper for 4.1 notes and write the Big Idea below.
Section 4.1 Landforms
Big Idea: Physical processes of the earth interact to form landforms.

2. Forces below Earth’s Surface
Geology-study of Earth’s physical structures & creation processes
Earth’s 4 zones
Core-inner (solid)and outer (liquid metal)
Mantle-magma &rock
Crust 5-25 miles thick
Remember the 2 branches geography – human and physical
We are going to focus on the physical
This is important because the physical and affect the human- have students give some examples
First we need to know how they are made which is the study of geology- ask a student to give the def from their vocab packet. Then pop up the def.
Before we can understand the landforms above we need to understand the ones below. We need to know how our earth is structured
The core of the earth is where radioactive material that is decaying generates heat.
Inner and outer
The inner is solid
The outer is mostly liquid and is made of nickel and iron
Mantle is next and is the largest –
The crust is next and makes the thinnest layer.
Magma sometimes make its way out of the earth like a pimple.

3. Plate Tectonics- Forces within create landforms
Internal Forces
Plate Tectonics- Forces within create landforms
Continental Drift-plates move along mantle
Volcanoes & Earthquakes -common along plate boundaries.
Earthquakes -tectonic forces causing rocks within the crust to break
Pangaea- super continent/ broke apart
-Plate tectonics explain how forces within the earth create landforms.
Earth is divided into many slow moving plates
Move about an inch per year-continintal drift
This all lead to stress of the plates, bending, breaking and eroding
Volcanoes can signify that plate boundaries are near by because of the lava
Earthquakes are signs of rocks breaking between plates
Pangaea- was the theory of Alfred Wegener who said that at one time all the continents were connected and then broke apart. Who could tell this for fossils left on all the continents.
Mid-Atlantic Ridge

4. What physical process forms ocean ridges?
Plate Movement
Plate move (apart/ spread, collide or laterally)
Spreading -ocean floor, magma works up=ocean ridge
Abyssal Plains-flat surface away from the ridges
Spreading plate boundaries on continents are called rift valleys
Continental Shelf
What physical process forms ocean ridges?
There are 3 types of plate movement: move apart(spread)/ collided/ laterally (past each other)
There are two types of earths crust-the lighter which the continents is made of and the heavier which is the ocean floor.
All spreading boundaries are found on the ocean floor and when the plates spread lava wells up which makes a chain of young volcanoes. This creates a mountain chain called an oceanic ridge. There is the mid Atlantic ridge that runs down the middle of the Atlantic Ocean. You cant see many of these mountains except for Iceland. Some spreading plates are directly under the continents and cause things called rifts where the land pulls apart. Madagascar it is assumed was created this way. by theses mountains are hydrothermal vents which are key to marine ecosystems. This is where heat is released from below the earths crust.
Show video of back smokers 5 min
Away from the oceanic ridges are the abyssal plain which is very flat under the ocean. These areas are usually made up of mud and clay sediments.
The continental shelf is the area of the ocean where you would swim right off shore. When you hit the end of it drops really fast to the abyssal plan.
Answer to question- rising lava that lifts the crust upward separating plates.

5. Plates Colliding
Trenches -plate sliding underneath the other
Folds rocks are compressed -bends
Faults rock masses broke apart moving away from each other.
Plate collisions =giant mountains
Plates moving Laterally slide past each other =earthquakes.
What types of different plate tectonics create mountains and earthquakes?
Colliding plates form both on ocean floors and continental ridges
On the ocean floor it is usually when the plates slide under each other. This is called a seduction zone the deep valley that is a result of this is called a trench
Folds are when you have a light plate with a continent on it and one that is heavier that is an ocean plate. The lighter slides under the other and create folds and faults. Folds are when the continental plate is pushed and the rocks have been compressed into bends.
Faults are when rocks have broken and moved away from each other. One might move up which causes mountains
Plate collisions like this can cause mountains like the Himalayas
Plates moving laterally slide past each other creating earthquakes.
Answer to question- mountains (plates collided) earthquakes (plates moving laterally)

6. How do wind, water and ice shape the land?
Forces on Earth’s Surface
Weathering-breaking & decaying of rocks( chemical & physical processes (heat, water and freezing)
Sediment-small particles (gravel, sand &mud)
Erosion-surface material move location
Water, Wind , Ice and Waves cause erosion
How do wind, water and ice shape the land?
As forces of the earth are being built up there are other forces that are tearing them down.
Weathering and erosion- rocks breaking and decaying over time. this is usually a slow process and hard to see. Examples of it are when there are the chemical process of water freezing and then thawing causing the rocks to crack. Or a tree root braking them apart as it grows.
When the rocks break apart through weathering they leave small particles of themselves called sediment.
Along with weathering there are other processes that change landforms. Erosion is the movement of surface materials from one place to another. This can be done through water, wind and ice.
Water is the strongest force in nature. it can cause rapid erosion if there are not enough plant roots to hold sediment in place. think of a rainstorm and the soil starting to wash way in streams and then becomes a gully. The Mississippi carries sediment all the way to the gulf of Mexico. Waves can change shore lines over many years.
Wind- where there is not a lot of vegetation leaves the soil open to be blown away by the wind or worn away by the wind.
ice is another way for landforms to change glaciers are build ups of ice that never thaw all the way and then refreeze during the cold times of the year. When these are at the tops of mountains and slide down as they melt they grid the ground creating more sediment. Over time they can even carve large valleys.
Click on the drawn diagram of the dun to show video of sand blowing all the way to south America.
Answer to question- wind ( blows sediment), water (washes away sediment), ices (grinds the ground into sediment).

7. Shapes on the land Divide into 3 different groups by how created.
1st Tectonic process
Mountains, valleys, volcanoes
2nd Erosion
Plateau- wind wore away loose sediment to reveal harder rock.
3rd Sediment deposits
Sand dune, floodplain
All these types of landforms are interconnected
sediment brought down from a mountain is washed away down a river to create an alluvial fan then it is washed further to create a delta