The world was not like this billions of years ago!
Pangea A scientist named Alfred Wegener came up with the Theory of Continental Drift. He said that the world billions of years ago was a supercontinent called Pangea. By the movement of plate tectonics he insisted that over the course of eons the continents formed into the landmasses that we know today.
Transform A transform boundary is where two plates are lying parallel to each other. When plates are close together like that and they move that causes shearing. When shearing happens it creates a fault in the crust(aka faulting). When tension rises between the two plates they create a strike slip fault. A strike slip fault is where rock strata are displaced horizontally, parallel to the fault line.
The plates move opposite of each other which is why shearing happens. Which is why faults are created.
Convergent A convergent boundary is where two or more plates collide into each other. When that happens subduction occurs where one plate is pushed down into the Earth by another plate. Since the oceanic crust is more dense than the continental crust, the continental crust is the one being pushed back down into the Earth.
Divergent A divergent boundary is where two plates move away from each other. The two plates move due to the convection currents in the mantle. When the convection currents move it takes the plates right along with it. When the plates spread apart, seafloor spreading occurs. Seafloor spreading is when there is an opening in the crust on the bottom of the seafloor, more magma comes through the gap and creates a new layer of rock. The Mid-Atlantic Ridge is an example of a divergent boundary. The plates collided together at the same time creating a 10,000 mile mountain range on the seafloor. It is the longest mountain range in the world.
Earthquakes When pressure is present between 2 plates they begin to move against each other and shake the crust. When this happens two different waves of energy are released: A P wave and an S wave. We use The Richter Scale to determine the power and strength of an earthquake. We also use a seismograph to graph the power an earthquake creates. An epicenter is a point that is directly above the focal point which is where the earthquake is happening. To determine where exactly the epicenter is we use triangulation. It shows the distance between three possible points of the epicenter and the focal point. Where all the points meet, that is where the epicenter is located.
Volcanoes Volcanoes are created from convergent boundaries colliding very hard. It creates an opening in the Earth, hence creating a volcano. There are thousands of volcanoes around the world, but the most active ones are around the RIng Of Fire. The Ring of Fire is a huge area of volcanoes around convergent boundarys that are always active. There are three different kinds of volcanoes: Shield, cinder cone, and composite. Shield volcanoes are made out of layers of hardened lava and are mostly flat on top. Cinder cone volcanoes are small cones made out of pyroclastic foam from explosive eruptions. Composite volcanoes, also known as stratovolcanoes, are the most common type of volcano. Formed from explosive eruptions and they alternate between explosive and nonexplosive eruptions. There are two types of eruptions: explosive and nonexplosive. Nonexplosive are gentle explosions with lava flowing down the side like a river. They are not as loud. Explosive are very loud explosions with lava and pyroclastic rock spewing out of the volcano and reaching for miles.