Geography - Geosphere, geomorphic processes and landforms

Geosphere

The solid component of Earth, including rocks, minerals, soils, landforms and Earth’s internal structure.

Geomorphic system

An interconnected system of landforms, energy flows and physical processes that shape and transform Earth’s surface.

Plate tectonics

The theory that Earth’s lithosphere is divided into moving tectonic plates whose interactions produce features and events such as mountains, earthquakes and volcanoes.

Plate motion

The precise scientific measurement of the movement of a tectonic plate, often measured in centimetres per year.

Plate movement

A general description of the direction or type of movement of tectonic plates.

Earthquake

The sudden release of energy caused by movement along a fault or tectonic plate boundary, producing seismic waves.

Volcanic activity

The movement of magma and associated materials to or towards Earth’s surface, commonly occurring at subduction zones and divergent plate boundaries.

Gradational processes

External processes that wear down, transport and deposit Earth’s surface materials, generally tending to reduce differences in relief.

Weathering

Weathering

The breakdown or alteration of rocks and minerals at or near Earth’s surface without the material being transported away.

Physical weathering

The mechanical breakdown of rock into smaller pieces without changing its chemical composition.

Chemical weathering

The breakdown or alteration of minerals through chemical reactions, often involving water, oxygen or carbon dioxide.

Soil formation

The long-term process where weathered rock combines with organic matter and is affected by organisms, water and climate to form soil layers.

Erosion, deposition and mass movement

Erosion

The wearing away and removal of rock and soil by agents such as water, wind, ice and gravity.

Deposition

The settling of transported sediment when the energy of the transporting agent decreases.

Mass movement

The downhill movement of rock, soil and debris under the force of gravity.

Weathering vs erosion

Weathering breaks down rock in place, while erosion involves the removal and transportation of material.

Erosion vs deposition

Erosion removes and transports sediment, while deposition occurs when transported sediment is dropped.

Landforms

Fluvial landforms

Landforms created by flowing water through processes of erosion, transportation and deposition, such as canyons, valleys and deltas.

Aeolian landforms

Landforms created by wind erosion and deposition, particularly in dry environments, such as dunes and yardangs.

Glacial landforms

Landforms created by moving ice through erosion and deposition, such as U-shaped valleys, corries and moraines.

Earth system connections

Geosphere–atmosphere interaction

Atmospheric conditions such as temperature, rainfall and wind influence weathering and erosion of Earth’s surface.

Geosphere–hydrosphere interaction

Water contributes to weathering, erosion, transportation and deposition, shaping Earth’s landforms.

Geosphere–biosphere interaction

Organisms contribute to soil formation and weathering, while vegetation can reduce erosion by stabilising soil.