Forces That Sculpture The Earth Flashcards
1
Q
- disintegration or alteration of rock in its natural or original position
- breaking down or dissolving of rocks and minerals on the surface of the Earth
A
WEATHERING
2
Q
TYPES OF WEATHERING:
- caused by the effect of changing temperature on rocks
- breaking down of rocks into smaller pieces without undergoing any change in mineral composition
A
Physical or Mechanical Weathering
3
Q
TYPES OF PHYSICAL OR MECHANICAL WEATHERING:
- usually occurs in mountainous regions like the Alps or Snowdonia
- happens when rainwater or snow-melt collects in rocks’ cracks then the water expands
A
Freeze-thaw
4
Q
TYPES OF PHYSICAL OR MECHANICAL WEATHERING
- occurs as cracks develop parallel to the land surface as a result of pressure reduction during uplift and erosion
- happens due to the combined effects of change in temperature and the expansion of minerals inside the rocks
A
✓ Exfoliation
5
Q
TYPES OF WEATHERING:
- caused by rain water (slightly acidic) reacting with the mineral grains in rocks to form new minerals and soluble salts
- occurs more rapidly at higher temperature like those in warm, and damp climatic regions
- first stage in soil formation
A
Chemical Weathering
6
Q
TYPES OF CHEMICAL WEATHERING;
- carbon dioxide in the air dissolves in rainwater making it weakly acidic
- weak carbonic acid is able to dissolve limestone as it seeps in the cracks and cavities, Acid Rain
- polluting gases like Sulphur dioxide and nitrogen dioxide dissolve in rainwater making it strong acid and when it attacks rocks, it leaves serious damage and breakdown
A
✓Solution
7
Q
TYPES OF CHEMICAL WEATHERING;
- breakdown of rocks by acidic water to form clay and soluble salt
- happens when acid rain reacts with rock- forming minerals like feldspar but quartz is the only common rock-forming mineral not affected by this Spheroidal Weathering
- rusty color
A
✓ Hydrolysis
8
Q
TYPES OF CHEMICAL WEATHERING
- breakdown of rock by oxygen and water, often giving iron-rich rocks a rusty colored weathered surface
A
✓ Oxidation
9
Q
TYPES OF WEATHERING:
- occurs when plants break up rocks with roots, prying the rock apart
- burrowing animals like badgers, moles and rabbits, burrow into rocks in search
- for shelter or food only refers to weathering caused by organisms such as animals, plants, fungi and microorganisms
A
Biological Weathering
10
Q
MAJOR CAUSES OF WEATHERING:
- occurs in the presence of water in regions with temperature near the freezing point (32 degrees Fahrenheit or 0 degrees Celsius)
- particularly common in Alpine areas and around the edges of glaciers
- when water seeps into a crevice in the rock and freezes, it expands causing deeper cracks and making rocks to eventually break apart
A
Frost Weathering
11
Q
MAJOR CAUSES OF WEATHERING:
- occurs when heat absorbed from the surrounding air causes a rock to expand; subsequent expansion and contraction when rock cools can cause thin sheets of rock’s outer layer to peel off
- moisture can also play a great role as well
- usually happens in desert areas where there is a variation in temperature suing night and day
A
Thermal Stress
12
Q
MAJOR CAUSES OF WEATHERING:
- caused when water get into rock in ways like up from a groundwater supply, action of seawater waves along rocky coast and downward through rainfall
- water evaporates, leaving salt behind which then crystallizes and the growing crystals can exert pressure on the rock that eventually break it
A
Salt Wedging
13
Q
MAJOR CAUSES OF WEATHERING:
- roots of trees and other plants can grow into small spaces and gaps between rocks, as they grow bigger they exert pressure on rocks around them causing a widening or gaps and cracks which result to breakdown microorganisms and lichens remove minerals from rocks making them weaker and when they are subjected to other forces
A
Biological Weathering
14
Q
FACTORS AFFECTING WEATHERING:
- rocks are subjected to weathering according to their composition; igneous are resistive to mechanical weathering but heavily affected by chemical weathering while some sedimentary rocks are subjected to mechanical weathering
- rate of weathering depends largely on the composition of the material that holds the grains together; rocks that are strongly jointed and fissured are more subjected to weathering than rocks with few cracks
A
Nature of Rock
15
Q
FACTORS AFFECTING WEATHERING:
- variation in climatic condition heavily affects the rapidness and slowness of weathering; regions with dry and cold climates tends to have relatively slow weathering processes compared to those regions with humid and warm climates
A
Climate
16
Q
FACTORS AFFECTING WEATHERING:
surrounding greatly phenomena influences weathering; altitude, slope of land, exposure to sun and rain all have their impacts on how rocks can be weathered
A
Topographic Condition
17
Q
-movement of weathered rock by wind, water, glaciers and gravity
-removal of surface material from Earth’s crust, primarily soil and rock debris
-transportation of eroded materials by natural agencies from the point of removal
A
EROSION
18
Q
TYPES OF EROSION:
- water is the most important erosional agent and erodes
- most commonly all forms of water can be erosional
- raindrops create splash erosion that moves tiny particles of soil
A
Water Erosion
19
Q
TYPES OF EROSION BY RAINFALL:
impact of a falling raindrop which can scatter tiny soil particles as far as six meters
A
Splash Erosion
20
Q
TYPES OF EROSION BY RAINFALL:
erosion caused by runoff
A
Sheet Erosion
21
Q
TYPES OF EROSION BY RAINFALL:
erosion that takes place as runoff develops into a discrete stream (rill)
A
Rill Erosion
22
Q
TYPES OF EROSION BY RAINFALL:
stage which in soil particles are transported through large channels
A
Gully Erosion
23
Q
TYPES OF EROSION
- also known as Aeolian erosion from the Greek God of winds, Aeolus
- erosion of this form is partially responsible for the formation of sand dunes
A
Wind erosion
24
Q
TYPES OF EROSION:
- The erosive power of moving ice is a bit greater than that of water
- glaciers perform erosive functions like they pluck and abrade
- plucking occurs when water enters cracks under glacier, freezing and breaking off pieces of rocks
- abrasion cuts into the rock under the glacier, scooping rock up like a bulldozer and smoothing and polishing rock surface
A
Ice Erosion
25
TYPES OF EROSION:
- waves in oceans and other bodies of water produce coastal erosion
- pure energy of waves along with the chemical content of water is what erodes coastline rocks
Wave Erosion
26
TYPES OF EROSION:
- erosion of permafrost along a river or coastline caused by warm temperature which makes ice-rich permafrost to break off and often carry valuable vegetation topsoil and
Thermal Erosion
27
FACTORS IMPACTING EROSION:
- perhaps the most influential force impacting effects of erosion
- includes precipitation, wind, and seasonal variability
Climate
28
FACTORS IMPACTING EROSION:
- The shape of the surface features of an area can contribute to how erosion impacts
- earthen floodplains of river valleys are prone to erosion unlike rocky flood channels; soft rock like chalk erode more quickly than hard rocks like granite
Topography
29
FACTORS IMPACTING EROSION
- can slow the impact of erosion because plant roots adhere to soil and rock particles preventing their transport during rainfall or wind events
Vegetation
30
FACTORS IMPACTING EROSION:
- areas like desert which lack thick vegetation often exposed to more erosion of landscapes
- responsible for the shaping of landscapes and thus influences the way erosion impacts tectonic uplift, for example, cay uses one part of the landscape to rise higher than others
Tectonic Activity
31
EROSION CONTROL:
- plowing in furrows which follow the contour of the land prevent formation of gullies by the direct flow of water down the slopes
Contour plowing
32
EROSION CONTROL:
arrangement of crops in alternate bands of row crops and cover crops which help to hold the soil
Strip cropping
33
EROSION CONTROL:
- construction of step-like ridges. following the contours of the field these hold or slow down the runoff water and prevent extensive erosion of the slope
Terracing
34
EROSION CONTROL;
- alternation of row crops one year with cover crops the next year arrests the early stages of erosion and allows small gullies to fill with soil
Crop rotation
