Mid-ocean Ridges

The mid ocean ridge is a under water mountain range,typically having a valley known as a rift running along its spine, formed by plate tectonics. The characteristics of this process is also known as ocean center spreading or sea floor spreading. The rising convection currents and divergent boundaries cause magma from the crust to rise. The magma pushes the plates apart and forms new land. A mid-ocean ridge is the boundary between two tectonic plates, and consequently, is known as a divergent plate boundary. Sea floor spreading is the result of continental drift. Continental drift is the fact that earth's continents drift on top of the mantle due to convection currents in the mantle.

Plate Boundaries

There are three kinds of plate boundaries, divergant, convergant, and transform boundaries.
Divergent boundareis are also known as a spreading center. At this center, two plates move apart from each other. When this process is in progress, the magma bubbles up to the surface and creates mid-ocean ridges. Divergent boundaries are responsible for the current motion of plates and sea floor spreading.

Convergent boundaries are also known as destructive plate boundaries. This is because of subduction, or when one plate sinks under another plate. When subduction occurs, plates collide and cause earthquakes. When plates fold a convergant boundary, mountain ranges form.

A transform boundary is a place where two plates slide by each other. An example of this is the San Andreas fault in California. Earthquakes also occur at these boundaries.

Evidence of Pangaea

We have much evidence that suggests that plate tectonics is real and it is still working now. A few examples of this are the way that South America and Africa fit together almost perfectly. Another piece of evidence suggests that fossils can also be a part of the puzzle. Fossils of animals that are located in Asia are located in California, USA. This proves that the continents were once together as one continent, called Pangaea, and drifted apart due to continental drift.

California's San Andreas Fault

The San Andreas Fault is approximately 880 miles long and runs through California. The fault is a transform plate boundary. The fault is also a boundary between the Pacific and North American plates. Professor Andrew Lawson discovered the fault at a lake in Northern California in 1895.

The Formation of the Earth

Here is a video about the formation of the Earth and plate tectonics.

The Layers of the Earth

The layers of the Earth are divided into separate regions. The layers are the crust, mantle, outer core, and inner core. The thickness varies depending on what they are made of. The crust is 5 to 40 kilometers deep. The mantle is 2885 kilometers deep. The outer core is 2270 kilometers deep. The inner core is 1216 kilometers deep.

The Ring of Fire

The ring of fire is ring of volcanoes along the edge of the Pacific Plate. The ring of fire is a area of constant seismic and volcanic activity. It is made of over 75% of the world's active and dormant volcanoes.90% of the world's earthquakes and 81% of the world's largest earthquakes occur along the Ring of Fire.

Plate Tectonics

The Theory of Plate Tectonics is the theory that the plates move due to continental drift and mid-ocean ridges. The biggest mountain range in the world, the mid-ocean ridge, is caused by plate tectonics.

Continental Drift/ Pangea

The Theory of Plate Tectonics includes continental drift and pangaea. Pangaea was a very large land mass. Sea floor spreading and continental drift caused it to spread apart as we know it today.