Landforms and Bodies of Water, Exogenic Processes Flashcards
A natural stream of water flowing in a channel to the sea, a lake, or another stream
River
An area of land that rises very
high above the land around it
and that is higher than a hill
Mountain
An area covered with sand or
small rocks that is next to an
ocean, sea, or lake
Beach
A large body of saline water
that separates continents
Ocean
An opening on the earth’s crust where pyroclastic
materials, lava, and gases come out
Volcano
Why do we have different landforms and bodies of water?
There are forces and processes that shape and change the structure of the earth and lead to the formation of these wonders.
- exogenic and endogenic processes
events that occur on the surface of the earth
- affected by external factors like solar energy (wind, water, etc.) and subsystems
- weathering, erosion, deposition, and sedimentation
Exogenic Processes
Events that are caused by the movement of materials in the Earth’s inner layer
- driven by Earth’s internal heat (geothermal energy)
- plate movement, magmatism, earthquakes, metamorphism, diastrophism
Endogenic Processes
the breaking down & changing of rocks as a result of exposure to the environment
weathering
Types of Weathering
- Physical/Mechanical - processes that break a rock or mineral into smaller pieces without altering its composition
- Chemical - accompanied by changing their chemical composition
Examples of Physical Weathering
- Exfoliation
- Frost Wedging
- Abrasion
- Plant/Root Wedging
- Animal and Human Activities
Cracking and peeling of the upper/outer rock
layers because it is weakened by:
- thermal expansion and contraction - repeated heating and cooling of materials cause rigid substances to crack and separate
- removal of overlying rocks - rocks underneath get exposed; there is less pressure on them, and they
expand. This causes the rigid layers to crack and sections to slide off
Exfoliation
cracking of rock mass by the expansion of water as it freezes in crevices and cracks
frost wedging/action
frost wedging in soil
permafrost
why does water expand when it freezes
When frozen, water molecules take a more defined shape and arrange themselves in six-sided crystalline structures. The crystalline arrangement is less dense than that of the molecules in liquid form which makes the ice less dense than the liquid water. When water freezes, the volume expands by approximately 9%.
Moving sediments or rock sections can break off
pieces from a rock surface they strike.
- The sediments can be moved by wind (in the desert), water, or ice, and the large rock sections by gravity.
- can be both weathering and erosion
Abrasion
As plants such as trees send out root systems,
the fine roots find their way into cracks in the
rocks. As the roots increase in size, they force the rock sections apart, increasing the separation and weathering.
plant/root wedging
how do human and animal activities cause physical weathering
- Some animals burrow themselves
on the ground. - Mining, construction, and
agriculture
