Plate Tectonics Vocabulary Terms

What is the Pacific Ring of Fire?

major earthquake zone that forms a ring around the pacific ocean, is a result of several convergent-subduction boundaries

Which layers of Earth have both solid and liquid sections?

mantle and core

What is continental drift?

A hypothesis proposed by Alfred Wegener in 1912 which stated that the continents moved and are STILL MOVING today. No one believed him until 1950.

What is the Lithosphere?

Area of solid rock that includes the crust but also the solid part of the upper mantle

What is a convergent-collision plate boundary?

Convergent is a scientific term for colliding or crashing plates. A Convergent Collision boundary is created when to plates "crash" into each other with equal force. Mountains form where the plates collide.

What is a divergent boundary?

Divergent is a scientific term for spreading plates. A rift valley forms between the plates.

What is the source of heat for the convection currents?

The core of the earth is hot because of radioactive decay. This heat is transferred through the mantle by convection currents.

How is the theory of Plate Tectonics similar to the process of recycling?

The earth recycles lithosphere (crust) just like we recycle plastics, metal, etc. Crust is created at divergent boundaries, and destroyed at convergent subduction boundaries. Then the process repeats. This process takes MILLIONS of years.

What is a Plate Boundary?

The edges where two (or more) tectonic plates meet

How did fossils help validate Wegner's hypothesis of continental drift?

The fossils of animals that could not swim or fly across the ocean were found on continents separated by oceans. This suggested that the continents with similar species were once connected.

What is Pangaea?

The name Wegener gave his super-continent he believed existed 300 million years ago as a result of continental drift

What is the crust?

The outer layer of Earth made of solid rock. It is 3-5 miles thick.

What is the asthenosphere?

The soft warm semi-solid layer of the mantle. It is responsible for making the plates move.

What is the Mid-Atlantic ridge?

The spreading of the sea floor in the middle of the Atlantic Ocean as magma forces the plates to move apart. The Atlantic ocean is actually getting larger as a result of this process.

What is the Theory of Plate Tectonics?

The theory that the earth's crust is made of large chunks of land, or plates, that move very slowly over time. The red arrows show how the plates are moving.

What are convection currents?

These are caused by very hot material at the deepest part of the mantle rising, then cooling and sinking again and then heating, rising and repeating the cycle over and over.

What is a Subduction Zone?

This is the zone where one tectonic plate gets forced under the other. The denser plate moves under the less dense plate.

What is the mantle?

This layer contains both solid and liquid rock. It lies just beneath Earth's crust. Scientists believe that this layer transfers heat from the core to the surface.

What is the inner core?

This part of the core is believed to be made up of solid iron. It is very dense and very hot (9000 degrees F).

What is the outer core?

This part of the core is made of melted iron and nickel having temperatures of 4000 degrees F. to 6000 degrees F. Surrounds the inner core.

What is a transform plate boundary?

Transform is a scientific term for sliding plates. The boundaries are rough and hold together for awhile and then suddenly move causing an earthquake.

What occurs at a transform boundary?

Very strong earthquakes occur at this boundary.

What occurs at a convergent collision boundary?

When plates smash into each other with equal force, mountains (sometimes called "folded" mountains) are formed. Valleys and earthquakes can be created at this plate boundary, too.

What occurs at a convergent subduction boundary?

When plates smash into each other, and one plate slips under the other, this can cause 1) magma to be released causing a volcanic eruption 2) volcanic mountains can form 3) a trench can form.

What occurs at a divergent boundary?

When the plates spread apart at this boundary, a rift valley forms, then the magma is released from the very hot asthenosphere filling in the valley. When it cools new land is created. The area in the center is younger than the area to the sides.

What are tectonic plates?

chunks of lithosphere that split, crash, and slide into each other on top of the asthenosphere

What do convection currents have to do with tectonic plates?

these currents cause the movement of the tectonic plates.