Tectonic Plates?

Leah B. 1/20/15 Period 6

Alfred Wagner believed that all the continents were once one continents called Pangea. All the edges and sides seemed to fit together. Eventually they drifted apart, creating the continents we have today. People didn't share this same theory with him. They wondered how all the continents we know today, fit together.
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Harry Hess and John Tuzo Wilson were the two scientists to believe Wagner's theory of continental drift. All the continents fit together like a puzzle piece. If you line up where fossils were found, they make a path. Still people did not believe this theory, even once they presented this new evidence.

Plate Boundaries

Bad Things:

Plate tectonics can cause multiple things like earthquakes and volcanic eruptions. Which later on these can lead to tsunami's. For example when a continental plate crashes with an oceanic plate, the oceanic plate slides under, because the continental crust is much bigger in size. So with all the moving around it causes an earthquake. In a divergent plate it seperates from eachother, which creates a spot for magma to flow through. That magma then creates the volcanos.

Good Things:

Plate tectonics can cause good things for us humans, not just buildings falling down and eruptions. They give us good fossil fuels. The heat and pressure create tiny pockets of gas and liquid petroleum. They also give us fertile soils. The weathering and breakdown of volcanic rocks give us the fertile soils. Last but certainly not least they give us ore deposits. The magma cools and hardens beneath a volcano and forms granite rocks.

Places where you can find these plate boundaries?

Convergent Boundaries: Himalayas
Divergent Boundaries: Mid-Atlantic Ridge
Transform Fault: San Andreas Fault

Plate Movement?

Geologists believe that convection currents are what cause the force for plate motion. Convection currents are found in the mantle. Once the currents reach the surface they begin to cool and sink back down to the surface. In the process trenches, volcanoes, and fault lines can form.

East Coast of North America vs. Mid-Atlantic ridge

The East Coast of North America is much older than the Mid-Atlantic ridge.

Why do you think this is the case?

It's Much older because the rocks along the Mid-Atlantic ridge are new rocks being formed, as for the East Coast of North America's rocks were made many years ago.

Convection Currents

Convection currents are found in the mantle.They help move the rigid plates that make up the earth.

Plate Boundaries

There are seven major plate boundaries in the world. There is the Pacific plate, Australian plate, South American plate, African plate, Antarctic Plate, Indian plate, and the Nazca plate.
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What do ocean trenches and plates tectonics have in common?

When a plate tectonic crashes with a oceanic crust it forms a trench. The ocean trench is old crust that gets pushed under the crust. It begins to form mountains under the water that can cause earthquakes, and even volcanos. That's something plate tectonics can create as well.

Sing Along

Plate Tectonics Song