Plate tectonics: margins and landforms

Plate tectonics is the scientific theory explaining the movement of the earth’s crust. It involves the formation, movement and subduction of the Earth’s plates.
The Earth’s crust is made up of several large and small tectonic plates that move relative to each other.
Plate boundaries can be classified into three types: divergent (constructive), convergent (destructive), and transform (conservative).

Divergent margins occur where plates move apart from each other.
One of the main landforms associated with this boundary is a mid-ocean ridge such as the Mid-Atlantic Ridge.
These create rift valleys, which are depressions formed by blocks of land between faults descending or from plates pulling apart.
Volcanic activity and geysers are prevalent along divergent boundaries due to magma reaching the surface.

Convergent margins occur where plates move towards each other, often forming mountain ranges like the Himalayas.
In oceanic-continental collisions, the denser oceanic plate subducts under the continental plate, forming a trench.
This subduction creates pressure within the mantle, creating magma which can lead to the formation of volcanic arcs.
In continent-continent collisions, plates crumple and fold, causing the formation of large fold mountains.

Conservative margins are boundaries where plates slide past each other, with no new crust being formed or destroyed.
Landforms are not mainly created at these boundaries, but they can form features like fault lines.
San Andreas Fault in California is a well-known example of a transform boundary.
The sheering force can cause intense earthquakes as plates judder past each other.

Landforms from plate tectonics are rich in minerals, making them important for human economic activity.
However, living near these areas is also dangerous due to the risk of earthquakes and volcanoes.
Knowledge of plate tectonics is vital for disaster management, such as predicting where earthquakes are likely to occur.
It is also important in planning and development, especially in hazard-prone zones.