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2. Relief
Opencast mining at Riotinto Mines, Huelva
4
crack (v)
:
break without completely
separating
5
canyon
:
deep, narrow valley with
steep sides, cut by a river
6
stalactite
:
column forming from the
roof of a cave from drips of dissolving
limestone
7
stalagmite
:
column forming on the
cave floor from dissolving limestone
deposits
Water
Water
, in all its different states, is the most important agent that shapes relief. Water
in seas and oceans shapes
coastal relief
; water in rivers and streams shapes
fluvial
relief
, and water in contact with rocks causes erosion (by wearing down or breaking)
or rock dissolution forms
karst relief
.
Wind
Wind
is present in all areas of
the planet. It erodes rocks and
transports sand and dust which
accumulate to forms
dunes
(small hills of sand). Dunes are
abundant in deserts and some
coastal areas. These landforms
are an example of aeolian relief.
The name comes from Aeolus,
the Greek god of the winds.
Temperatures
Extreme high or low
temperatures
cause rocks to crack
4
. When heat (which makes
rocks expand) and cold (which makes rocks contract) alternate, rocks break into pieces.
The action of human beings
Human beings
have always changed large areas of land for their own use. Quarries,
mines, tunnels and roads are all examples of the impact of human activity on the
landscape.
Orogenic processes, when tectonic plates push against each other, build mountain
ranges. Other agents also contribute to the
shaping of relief
. These agents are
water
,
wind
,
extreme temperatures
and the
action of human beings
.
3. THE SHAPING OF RELIEF
Coastal relief
This is the relief of
the coasts.
The action of waves shapes the
coastline by breaking off rocks
from the land and creating cliffs,
or by depositing sand or gravel,
forming
beaches
.
Coastal dune landscape
Cliffs and beaches are the main coastal
landforms.
