Earth & Space Science: Structure and Composition of the Earth

These flashcards cover key concepts regarding the Earth's layers, plate tectonics, types of rocks, geologic time, astronomical dating methods, and elements of our solar system.

Mantle

The uppermost layer of the Earth, approximately 2890 km deep.

Lithosphere

The layer that includes the crust and extends to 670 km deep.

Asthenosphere

The layer just below the lithosphere, thought to be relatively plastic based on seismic evidence.

Outer Core

The molten layer of the Earth located between 2890 km to 5150 km down.

Inner Core

The solid innermost layer of the Earth, extending from 5150 km to 6371 km.

Plate Tectonics

The theory explaining the interaction of six major lithospheric plates that causes geological phenomena.

Continental Crust

The part of the Earth's crust that forms the continents, formed from volcanic magma.

Oceanic Crust

The part of the Earth's crust that is covered by ocean, denser and thinner than continental crust.

Sedimentary Rocks

Rocks formed from the compaction and cementation of sediment.

Metamorphic Rocks

Rocks that have been transformed by heat and pressure.

Geologic Time Scale

A system of chronological dating that relates geological strata to time.

Radioactive Dating

A method used to determine the age of rocks and fossils based on the decay of radioactive isotopes.

Half-Life

The time it takes for half of the radioactive material in a sample to decay.

Terrestrial Planets

The four inner planets (Mercury, Venus, Earth, Mars) that are primarily composed of rock and metal.

Jovian Planets

The four outer planets (Jupiter, Saturn, Uranus, Neptune) which are primarily composed of gases.

Nebular Theory

The theory describing the formation of the solar system from a large cloud of gas and dust.

Supernova

A powerful and luminous explosion that occurs during the last stages of a massive star's life cycle.