Evidence For Plate Tectonics

Continental

A continent is a large continuous mass of land.

Fault

A crack in a body of rock along which rocks on opposite sides slide past each other.

Ocean Basin

A depression in the ocean floor that ranges from a few feet to several miles in depth.

Structure

A part of an organism; also refers to the way parts are put together.

Theory

A set of statements or principles devised to explain a group of facts or phenomena, especially one that has been repeatedly tested or is widely accepted and can be used to make predictions about natural phenomena.

Earthquake

A sudden shaking of the ground caused by the movement of rock underground.

Misconception 2: Does The Lava In Volcanoes Come Straight From Earth's Core?

Earth's core is made of solid iron, not magma, so lava cannot come directly from the core. Actually, most of the magma chambers that feed volcanoes are found in Earth's crust.

Magma

Melted rock located beneath Earth's surface.

Lava

Melted rock on Earth's surface.

Misconception 1: I always thought Earth was made of solid rock, and you could drill straight down to the core. Is that true?

The extreme heat and pressure of Earth's interior would prevent drilling down to Earth's core.

Tectonic Plate

One of several huge pieces of Earth's crust

What Is The Theory Of Plate Tectonics?

Plate tectonic theory states that the earth's lithosphere, or outer shell, is divided into several huge plates that glide on the slowly moving rock of Earth's surface. These plates move in a number of different directions, and their movement is responsible for geological events such as mountain formation, volcanic activity, earthquakes, and continental drift.

Continental Crust

Relatively thick crust that forms the continents, older and less deserve than oceanic crust, mostly made of granite.

Oceanic Crust

Relatively thin crust under the ocean basins, younger and more dense than continual crust, it is mostly made of basalt.

Crust

The layer of rock that forms Earth's surface.

Asthenosphere

The layer of soft but solid mobile rock found below the lithosphere.

Mantle

The layer of solid rock between Earth's crust and core.

Lithosphere

The part of Earth which is composed mostly of rocks; the crust and outer mantle.

How Does Earth's Structure Affect Plate Tectonics?

The tectonic plates glide over earth's mantle. Material in the mantle is constantly circulating as a result of heat within the mantle. As the partially molten rock flows, the tectonic plates move as well.

Plate Tectonics Theory

The theory that Earth's crust is made up of individual plates that gradually move in relation to each other.

Convection

The transfer of heat from one place to another caused by movement of molecules.

What Evidence Supports The Theory Of Plate Tectonics?

There is a great deal of scientific evidence in support of plate tectonics. Coastlines on opposite continents appear to fit together like puzzle pieces, indicating that they were once joined. Rock and fossils found in South America match those found in Africa, although there is an ocean in between. This also indicates that the two continents were once joined. Other evidence of plate tectonics include Seafloor spreading, which involves the creation of new crust at divergent plate boundaries.