Earth's Structure Flashcard

Front

Older crust type:

Back

Continental Crust

Answer explanation

The continental crust is older than oceanic crust. Continental crust can be billions of years old, while oceanic crust is continuously formed and recycled at mid-ocean ridges, typically being less than 200 million years old.

Front

Convection Current: Hot magma rises, cold magma lowers.

Back

Hot magma rises, cold magma lowers

Answer explanation

In a convection current, hot magma rises due to its lower density, while cold magma sinks as it is denser. This process creates a continuous cycle of movement, making 'Hot magma rises, cold magma lowers' the correct choice.

Front

Oceanic plate in a subduction zone:

Back

Pushed down into the mantle.

Answer explanation

In a subduction zone, the oceanic plate is denser than the continental plate, causing it to be pushed down into the mantle. This process leads to geological activity such as earthquakes and the formation of volcanic arcs.

Front

Divergent oceanic plate boundary creates:

Back

Mid Ocean Ridge

Answer explanation

A divergent oceanic plate boundary occurs where tectonic plates move apart, creating new oceanic crust. This process forms a Mid Ocean Ridge, which is characterized by underwater mountain ranges.

Front

Forms at a transform plate boundary:

Back

Fault Line

Answer explanation

At a transform plate boundary, tectonic plates slide past each other, creating stress that leads to the formation of fault lines. Unlike convergent or divergent boundaries, transform boundaries do not typically create volcanic features or trenches.

Front

A place where two plates slip past each other in opposite directions is a _______

Back

transform boundary

Answer explanation

A transform boundary is where two tectonic plates slide past each other in opposite directions. This movement can cause earthquakes, distinguishing it from divergent and convergent boundaries, which involve plates moving apart or together.

Front

Where two plates meet: _______

Back

convergent boundary.

Answer explanation

The correct answer is 'convergent boundary' because it refers to the area where two tectonic plates collide or come together, often leading to geological features like mountains or earthquakes.

Front

Ocean crust movement in sea-floor spreading.

Back

Diverging

Answer explanation

In sea-floor spreading, the ocean crusts are moving apart, which is known as diverging. This process occurs at mid-ocean ridges where new crust is formed as magma rises to the surface.

Front

Tectonic Plates

Back

Plates that move the Continents

Answer explanation

Tectonic plates are large sections of the Earth's lithosphere that move and interact with each other. This movement is responsible for the shifting of continents, making "The Plates that move the Continents" the correct choice.

Front

Pangaea

Back

super-continent that existed millions of years ago

Answer explanation

Pangaea is the name of the super-continent that existed millions of years ago, when all the continents were joined together. This distinguishes it from the other options, which do not accurately describe Pangaea.