Process: Geography

Common verb phrases

Verbs for saying that a phenomenon is taking place

happen when: Wind erosion happens when dry, exposed topsoil is removed from the land by the wind.
take place when: Cavitation takes place when bubbles of air collapse and cause shock waves against the banks.

Verbs for describing control of phenomena (also permit, let, stop, prevent)

allow: Continental drift occurs when ocean floors are sucked into the mantle by a process called subduction and this allows continents to collide.
control: Hot rock rising from deep inside the earth and its sideways flow when cooling are thought to be factors controlling the positions of oceans and continents.

Verbs for describing outcome

help: Longshore drift helps to add more material to the beach and helps to build it higher than before.
become: When air is heated it becomes lighter and rises forming low pressure.
get: Descending air gets warmer holdingits moisture in the form of gas. Note: gets is used like becomes, but is much more common.

Verbs for describing tendency

tend to: Light, warm air tends to rise, creating low pressure.
be prone to: Loose material is prone to movement.

Verbs which are used to give examples, aspects and factors

involve: Mechanical weathering involves rocks being broken up into smaller fragments.
include: The work of the sea along coastlines includes erosion, transport and deposition.

Verbs for talking about what is generated by a process

produce: Because peat is compressed into bricks it produces a lot of heat when burnt.
create: Migration of young men to towns and cities creates lower marriage rates in rural areas.
form: Rocks are continually being formed, changed and then destroyed by tectonic processes.
give off: Bituminous coal gives off fairly high levels of smoke and SO² when burned.

Noun phrases

phase: When land rises due to uplift, sea levels fall and rivers get a new base level, then the middle and lower river courses begin a new phase of vertical erosion.
period: A batholith is a dome-shaped mass of granite rock cooled from magma deep within the earth’s crust during a period of mountain-building.
stage: In the early stage of karst formation, the surface limestone is dissolved and erodes away.

Structures

For example: When a happens, it becomes …, + gerund …; As a happens, the b happens; If a happens, then b happens / will happen.

Note: the + gerund construction is given in the first example, but it is possible to find it used for adding description to all of the structures above.

when + -ing: When a wave retreats, it allows a rapid expansion in the compressed air, creating an explosive effect that widens cracks and shatters the rock face.
as + -ing: As the earth cooled, heavier materials sank and lighter materials stayed at the surface, forming different layers of the earth’s crust.
if + -ing: If freeze–thaw occurs on steep mountain slopes, then the pieces of rock slide down the sides gathering at the bottom of the mountain.

Sequencing phrases

first … then … finally: First a cave is formed, then an arch and finally a stack.
later: Long, deep river hollows later filled to form ribbon lakes.
eventually: Benefits of economic growth eventually move down even to the poorest people, making everybody better off in the long run.