Midterm review Flashcards
Exogenic Vs. Endogenic
Exogenic: Outside processes - Processes that occur on the earth’s surface - generally reducing relief Eg) Erosion
Endogenic: Inside - Processes that occur in the earth’s interior - creates relief by elevating mountains
Geosphere
Rocks comprising the earths crust and global tectonic systems
Hydrosphere
Oceans, atmosphere, surface and subsurface water
Biosphere
living organisms apart of the ecosystems
Overview of a land form
1) Volcanic and tectonic processes (Endogenic) - Processes bring fresh rock to the surface and create primary land forms
2) Geomorphic processes (Exogenic) - Cause land denudation: Weathering and erosion
- Denudation of primary landforms produces secondary landforms
Fold Belts
Fold belts are formed due to the compression of flat sedimentary strata initiated by continental collision
Types of folds
- Symmetrical
- Asymmetrical
- Overturned
- Recumbent
What is a normal fault?
Vertical movement of crustal blocks along steep fault plane
Reverse fault?
One block riding up over the other , producing very steep fault scarps
Overthrust fault
One block rides up on top of the other along a reverse fault plane
Transcurrent Fault
Horizontal movement of crustal blocks along a nearly vertical plane
Define Weathering
Breakdown of rock and mineral material by physical and chemical means, without transportation
2 breakdowns: Physical and chemical
What are some factors that control the process of weathering?
Climate Orientation of slope Bedrock geology Vegetation cover Surface area
Define Physical weathering
Rock disintegration without chemical alteration
Some types of physical weathering
1) Frost action
2) Salt crystal growth
3) Unloading
4) Thermal expansion
5) Root growth
What is chemical weathering?
Breakdown of minerals and rocks as a result of chemical alteration
Types of chemical weathering
1) Hydration
2) Hydrolysis
3) Oxidation
4) Chelation
5) Solution and carbonation
What is the formation of soil called?
Pedogenesis
What are the types of soil forming processes?
1) enrichment (Gain)
2) Removal (loss)
3) Translocation
4) Transformation
What is the recurrence interval?
Reciprocal of the chance or probability that the event will occur in any year
- p = 1/RI
What are the precip generation mechanisms? (3)
1) Creation of saturated conditions
2) Condensation of water vapour into liquid water
3) Growth of small droplets by collision and coalescence until they become large enough to precipitate
Frontal system
A weather front is a boundary separating two masses of air of different densities, and is the principal cause of meteorological phenomena.
Cold front
- A cold air mass lifts a warm air mass aloft
- Upward motion sets off a line of thundertstorms
- Cold front approaching = high intensity
Warm front
- Warm air advances toward cold air and rises up and over the cold air
- Rain falls from the dense stratus cloud layers
- Warm front approaching = Low intensity
What is field capacity?
Moisture content remaining when the soil has been drained by gravity - Eg) over a time period - 48hrs
Difference between soil and ground water?
Ground water has no air space (No pore space available) the water is saturated
Soil water potential
The potential for water to flow - water will move from higher head to the lower head
Hydraulic gradient
The difference in hydraulic head per unit of distance
Hydraulic conductivity
The measure of the ability for water flow in a ports media
- smaller the pore the smaller the conductivity
What are the retention forces?
Adhesion: Attraction of water to the pore sides
Cohesion -Attraction to water
Darcy’s Law
A description of the flow of fluid through a porus medium
Darcy’s Law - Equation
Q = -KA dh/dl
Q = Rate of flow K = Hydraulic conductivity A = Cross sectional area dh/dl = hydraulic gradient, that is, the change in head over the length of interest.
infiltration rate
The rate at which water infiltrates the surface of a soil
infiltration capacity
Max rate at which water can infiltrate a soil
Factors affecting the infiltration rate
- Soil conditions (Texture,structure,porosity,density,compaction,moisture)
- Precip characteristics
- Surface geography
- Human impacts
Matrix flow
Slow and even movement of water through a soil
Preferential flow
Rapid and uneven flow through soil
Runoff
Surface runoff (also known as overland flow) is the flow of water that occurs when excess water flows over the Earth’s surface.
What is a hydrography?
-Measures stream discharge - A graph showing the m3/sec and the time taken (hrs)
What is a hillslope?
A strip of land surface that is inclined - elevated land between valley bottoms
Hillslope process?
Movement of rock and soil by mass wasting, rain splash, and overland flow
Hortons hypothesis?
In soil science, Horton overland flow describes the tendency of water to flow horizontally across land surfaces when rainfall has exceeded infiltration capacity and depression storage capacity.
Some hillslope erosional processes
Rainsplash
Sheet wash
Soil creep
Mass wasting
Main factors of mass wasting
Gravity, slope and cohesion
When does slope failure occur?
When the driving forces are greater than the resisting forces
Difference between Rotational and translational slides?
Rotational: Downward and outward movement of a mass on top of concave upward failure surface
Translational: Translational landslide is a mass that slides downward and outward on top of an inclined planar surface
What factors affect the type of mass wasting?
- Material type
- Water content
- Rate of mass movement
- Movement type
debris flow
Flow of muddy water with a large amount of coarse material
What is solificution?
Rapid soil creep
- soil and rock are saturated and flow downslope
- Common in sub polar regions
