Unit 2: Dynamic Earth Review

Formation of the Solar System

The process by which the Sun and planets formed from a rotating disk of gas and dust.

Nebula

A giant cloud of gas and dust in space, the birthplace of stars.

Accretion

The process by which particles combine and grow in size, leading to the formation of planets.

Planetesimals

Small celestial bodies that formed in the early solar system and collided to form larger bodies.

Angular Momentum

The quantity of rotation of an object, which is conserved in the absence of external forces.

Lithosphere

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

Asthenosphere

The semi-fluid layer beneath the lithosphere that allows for the movement of tectonic plates.

S waves

Secondary waves, a type of seismic wave that moves through the Earth during an earthquake and cannot travel through liquids.

P waves

Primary waves, a type of seismic wave that is the first to arrive at a seismic station and can travel through solids and liquids.

Focus

The point within the Earth where an earthquake originates.

Epicenter

The point on the Earth's surface directly above the focus of an earthquake.

Theory of Continental Drift

The hypothesis proposed by Alfred Wegener stating that continents move and were once joined in a single landmass.

Alfred Wegener

A German meteorologist and geophysicist who proposed the theory of continental drift.

Divergent Boundaries

Locations where tectonic plates move apart, often leading to rift valleys and volcanic activity.

Convergent Boundaries

Boundaries where tectonic plates collide, which can lead to subduction zones and mountain formation.

Transform Boundaries

Boundaries where tectonic plates slide past each other, leading to earthquakes.

Mantle Convections

The process of heat transfer in the mantle that drives the movement of tectonic plates.

Ridge Push

A process that contributes to plate movement, where new oceanic crust is pushed away from mid-ocean ridges.

Slab Pull

The force exerted by a sinking plate that pulls the rest of the plate along with it into the mantle.

Cratons

Stable portions of the continental crust that have survived the cycles of plate tectonics.

Hot Spots

Volcanic regions fed by underlying mantle that are not located at tectonic plate boundaries.

Hawaiian Island Chain

A series of islands formed by volcanic activity originating from a hot spot in the oceanic crust.