Plate Boundaries: Processes and Landforms Explained

What happens at constructive margins?

Two sets of plates diverge, allowing magma to rise and form mid-ocean ridges and sub-marine volcanoes.

What is the Mid-Atlantic Ridge?

A mid-ocean ridge formed by the divergence of the North American and Eurasian plates, and the South American and African plates.

What is the temperature of the Earth's core?

Approximately 6000°C.

What causes magma to rise in constructive margins?

Magma becomes less dense when heated in the mantle and rises due to convection currents.

What type of activity occurs at constructive margins?

Gentle earthquakes and volcanic activity.

What landforms can be created at constructive margins?

Islands such as Iceland can form along the ridge.

What occurs at destructive margins (oceanic-continental)?

The denser oceanic Nazca plate subducts beneath the lighter continental South American plate.

What is formed at the subduction zone of the Nazca plate?

The Peru-Chile trench is formed.

What geological activity is caused by subduction?

Friction melts the subducting plate, causing earthquakes and volcanic eruptions.

What volcano is an example of destructive margins (oceanic-continental)?

Mt. Cotopaxi.

What landforms are created by compression at destructive margins?

Fold mountains such as The Andes.

What happens at destructive margins (oceanic-oceanic)?

The denser North American plate subducts beneath the Caribbean plate.

What trench is associated with the North American and Caribbean plates?

The Puerto Rico deep ocean trench.

What is formed as a result of subduction in oceanic-oceanic margins?

Island arcs such as the Lesser Antilles.

What volcano is an example of destructive margins (oceanic-oceanic)?

Mt. Pelée on the island of Martinique.

What occurs at continental collision zones?

Continental plates collide, causing land to buckle and compress, forming fold mountains.

What mountain range is formed by the collision of the Indo-Australian and Eurasian plates?

The Himalayas.

What is the movement rate of the Indo-Australian plate?

Approximately 5 cm/year.

What is characteristic of conservative margins?

Plates slide past each other, causing earthquakes without volcanic activity.

What is the San Andreas Fault?

A conservative margin where the Pacific Plate moves faster than the North American Plate.

What happens when plates lock at conservative margins?

Friction builds up pressure, which is released as earthquakes.