Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
How does the Earth's surface change over time?
Transcript of How does the Earth's surface change over time?
The crust is the thinnest layer. It is made of solid rock. The crust is cooler than the other layers in temperature. The crust is located on top of the mantle.
The inner core is located in the middle of the earth. It is shaped like a solid ball. The inner core can be from 5000'C to 5700'C. It is made of iron, silicon and carbon. The inner core is approximately 2,600 km or 1,600 miles in diameter.
The upper mantle is in between the lower mantle and the crust. The upper mantle is about 1000’C. The upper mantle is mostly made of solid rock. The mantle is the most large and complex layer.
The lower mantle is located above the outer core and under the upper mantle. The lower mantle is approximately 2500’C. It is mostly made of melted rock because of the heat from the core.
The outer core is located between the inner core and the mantle. It is 4000'C or more. The outer core is made of liquid iron and nickel, and the liquid iron and nickel are usually melted because of the hot tempurature. The outer core is approximately 2,250 km or 1,250 miles thick.
The Layers of Earth
Sedimentary rocks are made when layers of sediments are bunched together to form a sedimentary rock. Sediments are sand, mud and goop. There are 2 ways where this type of rock can be formed: cementation and compaction. Cementation is where sediments are held together by another material. Compaction is where layers of sediment are just squished together. Cementation and compaction both make sedimentary rocks.
Igneous rocks are formed when hot magma or lava cools and becomes a solid. Igneous rocks can be classified as extrusive or intrusive. Extrusive rocks are molten material that cooled on the earth's surface, while intrusive rocks are molten material that cooled below earth's surface. Both extrusive and intrusive rocks are igneous rocks.
Metamorphic rocks are made when heat, pressure or fluids change the rock's minerals, therefore changing the rock itself. All rocks can be formed into a metamorphic rock but the process of turning it into a metamorphic rock is very slow. There are 2 types of metamorphic rocks: thermal & regional. Thermal metamorphic rocks are rocks formed by heat. Regional metamorphic rocks are formed by pressure.
Rocks are always born as igneous first. When lava or magma cools down to form a rock, that is an igneous rock.
When an igneous rock breaks, erosions shapes the rock, sediments fall and they are squeezed together to form a rock that is called a sedimentary rock.
When the sedimentary rock's form changes from heat, pressure or fluids, that rock is called a metamorphic rock. Once the metamorphic rock melts, it turns into lava or magma, and once it cools again it will become an igneous rock once again.
The Rock Cycle
Convection currents are movements of hot and cold materials from the asthenosphere. When rocks melt and become magma, the hot magma rises up to where the crust is while the cold material sinks down nearer to the center of the earth. COnvection currents are able to move the plates above the asthenosphere which can form volcanoes, earthquakes, mountains and new crust.
Water can change the surface of our land because when water continuously moves over a surface, it changes the form of a rock or it can create rivers or creeks
Glacier erosions can change the surface of our land because they can freeze, carve and shape parts and the land will change overtime slowly.
Wind erosion can change the surface of our land because the wind can blow the gritty sand onto rocks, therefore changing the texture of rocks. It can also create small mountains with sand
Fossils are found in sedimentary rocks, like limestone and shale. Fossils preserve the hard parts of plants or animals, and the soft parts decay. There are different types of fossils, like martella or coiled ammonites.
Divergent Plate Boundary
Divergent plate boundaries are formed when plates separate. Divergent plate boundaries can create volcanoes, new crust and even earthquakes. When divergent plate boundaries create new crust, I think this relates to sea floor spreading because when there is a rift in the sea floor, magma can flow from that crack and coo, to create new magma.
Convergent Plate Boundary
Convergent plate boundaries are formed when plates are crashing and colliding into each other. Convergent plate boundaries can create small hills, mountains and earthquakes. When the plates crash into each other, it forces the crust to come up and create mountains and hills. While this happens, earthquakes can occur.
Transform Plate Boundary
Transform plate boundaries are formed when plates move side-to-side, sliding past each other. Sometimes, earthquakes can happen from transform plate boundaries from rocks in the plates breaking when sliding side to side.
The asthenosphere is in the lower mantle and the lithosphere is in the upper mantle and the crust.
Subduction is where an oceanic crust collides with a continental crust, but the oceanic crust sinks under the continental crust because it is heavier and more dense. Subduction can form mountains.
Continental Drift Theory
The continental drift theory was created by Wegner. This theory was that all the continents were together as one piece of land which was called Pangea. The continents fit together just like a puzzle piece, and Wegner thought that the continents must have drifted apart from each other. When the continents were put together, Wegner noticed that the different types of fossils were found together as well.
Many scientists create theories using clues that they have learned about.Using clues, scientists were able to prove if their theories were right or wrong.
Tectonic Plate Theory
Convection currents in the asthenosphere dragging the tectonic plates are what's causing tectonic plates to move, according to the tectonic plate theory. Whhichever way or direction the plates move, mountains, small hills, volcanoes and earthquakes are formed from the 3 different types of plate boundaries.
Sea-Floor Spreading Theory
When two divergent plates are spreading apart in the sea floor, a rift in the seafloor is formed. When magma from the earth comes up from that crack, the magma cools overtop of the old crust and cools from the water to create new crust. Once the plates spread again, the new crust that the magma created will be old crust, and a new rift will form and magma will come again to create new crust once again,