Plate Tectonics

By: Jess Ciesla

What is Plate Tectonics?

Well the basic idea of plate tectonics is that there are eight major plates, & many smaller plates on the surface of the Earth. The plates are constantly moving even though it might be only centimeters per year, at one point scientists believed that all of the plates were combined creating the super continent Pangea.

Plate boundaries

There are 5 different kinds of plate boundaries and these are transform, divergent (in ocean), divergent (continents), convergent with subduction, and convergent continents. The transform boundary is where the two plates slide against each other, and the grinding of the plates causes Earthquakes two good examples of this boundary is the San Andreas Fault in California, and also the Earthquakes in Irving, Texas. Both of the divergent boundaries are two plates splitting apart the difference is one of the boundaries in in the ocean, which causes volcanoes and sea floor spreading, a good example of this is the Mid-Atlantic Ridge. Now divergent continents is on land which mostly causes rift valleys, and a great example of this is the country of Iceland. Convergent boundaries are two plates colliding with each other causing trenches and mountains such as the Mariani's Trench in Hawaii and the Himalayas mountains.

Three main layers of the Earth

The crust, mantle, and core are three main layers of the Earth. The crust is the outermost solid shell, the mantle is the sylicidic rock rich in magnesium and iron under the crust, the core is made up of the inner and outer layer of the Earth.

Continental Drift

In 1912 a man named Alfred Wegner, created the theory of continental drift by using old fossil records, and the other was that the continents seemed to fit together into one big puzzle piece, quite simple actually. What is continental drift? This is the movement of Earths continents, which is why we have seven continents on Earth today.

Sea Floor Spreading

A man named Harry Hess proposed the theory of sea floor spreading in the early 1960's, sea floor spreading is a process that occurs at mid-ocean ridges where new oceanic crust is formed by volcanoes rising, this process actually helps explain the theory of continental drift. oceanic plates split or diverge ,tensional stress causes fractures to occur in the lithosphere which causes the magma to rise creating new sea floor, that's pretty cool huh?


According to the Webster's dictionary convection is "heat transfer by mass motion of a fluid such as air or water when the heated fluid is caused to move away from the source of heat, carrying energy with it". Convection helps plate movement because, the hot air lifts up the plates allowing them to move. Which is why our plates move!

Ring Of Fire

The Ring of Fire is an area where a large number of earthquakes and volcanic eruptions occur in the basin of the Pacific Ocean, Google says "In a 40,000 km (25,000 mi) horseshoe shape, it is associated with a nearly continuous series of oceanic trenches, volcanic arcs, and volcanic belts and/or plate movements." Which means that the Ring of Fire is significant because the volcanic eruptions and trenches help with the plate movement.