02_The Earth Interior

A set of vocabulary flashcards derived from the lecture notes on the structure, composition, and properties of Earth's layers.

Seismic Waves

Waves of energy that travel through the Earth's interior, generated by earthquakes.

Isostasy

The equilibrium between the Earth's crust and upper mantle, where the crust floats on the viscous mantle.

Lithosphere

The rigid outer layer of the Earth, consisting of the crust and the uppermost part of the upper mantle.

Asthenosphere

The partially molten layer of the upper mantle that behaves like a viscous fluid.

Core

The innermost layer of the Earth, primarily composed of iron (Fe) and nickel (Ni).

P Waves

Primary waves, a type of seismic wave that compress and expand material.

S Waves

Secondary waves, a type of seismic wave that shears material and cannot pass through liquids.

Moho Discontinuity

The boundary between the Earth's crust and the underlying mantle.

Convection

The movement caused within a fluid by the tendency of hot material to rise and cool material to sink.

Crust

The outermost layer of the Earth, consisting of oceanic and continental crust.

Mantle

The layer of the Earth between the crust and the core, consisting of solid rock that flows slowly.

Outer Core

The liquid layer of the core, lying beneath the mantle and above the inner core.

Inner Core

The solid innermost layer of the Earth, composed primarily of iron and nickel.

Geodynamo

The process that generates Earth's magnetic field through the motion of conductive fluids in the outer core.

Geotherm

The rate of temperature increase with depth in the Earth.

Shadow Zone

Areas on the Earth's surface where no seismic waves from a given earthquake can be detected.

Density

The mass per unit volume of a substance, significant in geological structures and isostatic calculations.

Gravity

The force of attraction between objects with mass, influencing isostatic balance.

Crustal Root

The deeper part of the crust that extends below mountain ranges, contributing to mountain height.

Compression

A type of stress that occurs when rocks are squeezed together.

Shear

A type of stress that causes layers of rock to slide past one another.

Archimedes Principle

The principle stating that an object immersed in a fluid is buoyed up by a force equal to the weight of the fluid displaced.

Brittle

A property of rocks that indicates they will break or shatter under stress instead of deforming.

Plastic

A property describing materials that can flow or deform under stress without breaking.

Temperature Gradient

The rate at which temperature changes with depth within the Earth.

Basaltic Rocks

Rocks formed from basalt; typically found in oceanic crust and rich in iron and magnesium.

Granitic Rocks

Rocks composed mainly of quartz and feldspar; common in continental crust.

Peridotite

A dense, coarse-grained rock composed mainly of olivine, found in the upper mantle.

Buoyancy

The ability of an object to float in a fluid, related to isostasy.

Rebound

The process by which the Earth's crust rises after being depressed by weight, such as from ice sheets.

Thermal Expansion

The increase in volume of materials as they are heated.

Tectonic Plates

Massive slabs of Earth's crust that move and interact at their boundaries, causing earthquakes and volcanism.

Upper Mantle

The upper layer of the mantle, directly beneath the crust.

Lower Mantle

The portion of the mantle located below the upper mantle, reaching down to the outer core.