Chapter 12 Learning Objectives
1. What are the major energy resources found in rock and sediment, how do they form and how are they recovered? Specifically, for oil, gas, and coal?
a. Kerogen: the waxy molecules into which the organic material in shale transforms when reaching 80 C. at higher temps, kerogen turns into oil
b. Oil, gas, and coal are fossil fuels, and solar energy is stored into these fossils that formed from organisms long ago
c. Oil and gas consist of hydrocarbons: organic chemicals made of chain like or ring like molecules made of carbon and hydrogen atoms
d. Hydrocarbon type (natural gas, gasoline, oil, tar) is a function of chain length
e. Coal is a black brittle sedimentary rock that burns-it does not have the same composition or origin as oil
2. What needs to be present and at what temperatures to make a good oil recovery site? What is the oil window, source rock, seal rock, porosity, permeability, etc.?
a. Oil window: the narrow range of temperatures under which oil can form in a source rock (90-160 C)
b. Source rock: a rock (organic rich shale) containing the raw materials from which hydrocarbons eventually form
c. Seal rock: a relatively impermeable rock, such as shale, salt, or unfractured limestone, that lies above a reservoir rock and stops the oil and/or gas from rising further
d. Porosity: the total volume of empty space (pore space) in a material, usually expressed as a percentage
e. Permeability: the degree to which a material allows fluids to pass through it via an interconnected network of pores and spaces
f. Reservoir rock: a rock that contains (or could contain) an abundant amount of easily extractable oil and gas; these rocks have high porosity and permeability
3. What does the energy consumption of the US look like? What do we use for energy production?
a. 19% of the global energy consumption, mainly fossil fuels We also discuss several other topics like In primate adaptive trends kingdom means what?
4. What are the renewable and nonrenewable resources?
a. Renewable: a natural resource that can be re-made/re-grown quickly
b. Nonrenewable: a natural resource that cannot be re-made or re-grown at a scale comparable to its consumption
5. What are the common mineral resources and how do they form and how are they extracted?
a. Limestone, crushed stone, siltstone, granite, marble, slate, gypsum, phosphate, pumice, clay, sand, salt, sulfur (chart in slides)
Chapter 13 Learning Objectives
∙ Mass movement: (mass wasting) is the downslope motion of rock, regolith (soil, sediment, debris) snow, and ice.
∙ Creep: the slow downhill movement of regolith due to seasonal expansion and contraction of regolith
∙ Solifluction: the slow downhill movement of tundra If you want to learn more check out What is the meaning of misdemeanor?
∙ Slumping: mass movement by sliding or regolith as coherent blocks ∙ Mudflow: a slurry of water and fine sediment If you want to learn more check out What is the meaning of product complexity?
∙ Debris flow: a mudflow with many large rocks
∙ Lahars: volcanic ash from recent or ongoing eruptions mixes with water from heavy rains or melted glacial ice
∙ Avalanche: turbulent cloud of debris and air
o Snow avalanche: a thick mass of over steepened snow that detaches from a mountain peak
o Wet: viscous slurry, hugging the slope and entraining little air. Move relatively slowly
o Dry: move cold, powdery slow. Above the ground surface on a layer of pressurized air, move rapidly
∙ Turbidity current: move as a turbulent cloud of suspended sediment that deposit graded beds
∙ Initiating mass movements
o Occur when earth materials that has been weakened by weathering. Chemical and physical weathering produce regolith. Surface material is much weaker than solid crustal rock
∙ Steeper slopes create a larger force imbalance
o Downslope forces-gravity
The weight of earth materials
The weight of added water Don't forget about the age old question of What does cultural convergence theory argue about globalization and culture?
The weight of added structures
o Resisting forces-material strength
o Chemical bonds
o Electrical charges
o Surface tension
∙ Angle of repose: the steepest angle of descent or dip relative to the horizontal plane to which a material can be piled without slumping (on the verge of sliding)
∙ Slope change: slope characteristics can destabilize a slope. Loading the top of a slope with added weight, steepening a slope beyond the angle of repose
∙ Important factors affecting slope strength
o Relief: steeper slopes have more mass movement
o Climate: more rainfall creates larger water problems and accelerates rates of chemical weathering
∙ Preventing mass movements
o Revegetation: roots stabilize the potential failure plane
o Regrading: terrace steps
o Drainage: potential failure plane dries and becomes stronger o Reducing undercutting
o Engineering structures
Chapter 14 Learning Objectives
1. What are the characteristics of a stream channel? Where is erosion and deposition occurring and how will the channel evolve?
a. Stream formation
i. Precipitation occurs
ii. Sheetwash flows downhill
iii. Flowing water digs tiny channels called rills
iv. Rills downcut; develop into streamflow
b. Headward erosion: the process by which a stream channel lengthens up its slope as the flow of water increases
c. Drainage network: an array of interconnecting streams that together drain an area
d. Erosion is usually occurring on the outer banks, while deposition occurs on the inside.
e. High energy=sediment erosion/transportation
f. Low energy=sediment deposition
g. Fluvial deposits(alluvium): sediment deposited in a stream channel, along a stream bank, or on a floodplain
h. Point bar: a wedge-shaped deposit of sediment on the inside bank of a meander
i. Delta: a wedge of sediment formed at a river mouth when the running water of a stream enters standing water, the current slows, the stream loses competence, and sediment settles out
2. What are the major drainage network patterns?
3. How do rivers carry sediment and what is stream competence and capacity? a. The total volume of sediment is referred to as the sediment load
b. Dissolved load: water seeping through rock surrounding stream channel dissolves certain minerals and transports these ions down the stream
c. Suspended load: small solid particles (silt or clay size) that swirl along in the water without settling to the floor of the channel
d. Bed load: larger solid particles (sand, pebbles, or cobbles) that that bounce or roll along stream floor
e. Stream competence: refers to the maximum particle size a stream can carry
f. Stream capacity: refers to the total quantity of sediment it can carry (depends on competence and discharge)
4. How is discharge calculated and measured?
a. Discharge: area of the stream times average stream velocity b. D=A_c times v_a D=(100m^2) times (10m/s) D=1000m^3/s
5. What is base level?
a. The lowest elevation a stream channel’s floor can reach at a given locality
b. Ultimate base level is sea level (sea level can move up and down). A lake (natural or man-made) represents a local base level
c. A stream “tries” to erode down to base level (slow process) 6. What is a flood recurrence interval and why is it important?
a. The average amount of time it takes for the same discharge level to occur again. Helps to predict nature of floods
Chapter 15 Learning Objectives
1. What is the bathymetric profile of the oceans?
a. The study of the underwater depth of lake or ocean floors. In oceans, the highest point is in the middle of the ocean
2. How do temperature and salinity change throughout the climate zones of Earth and how does this effect circulation?
a. Salinity is a function of:
i. Water temperature (warm water holds more salt)
ii. Addition of freshwater from river runoff, groundwater, ice melt, and direct rain
iii. Evaporation rate at ocean’s surface
iv. Ocean currents (fast vs. slow)
v. Most ocean water is cool to cold, with the greatest difference is temperature by depth in the tropics
vi. Warm water from the tropics is transported to the poles by currents (more solar radiation)
3. What is the Coriolis force and how does it effect circulation in the northern and southern hemispheres?
a. Coriolis effect: the deflection of objects, winds, and currents on the surface of the earth owing to the planets rotation
4. How are tides formed and at what alignment of the Moon, Sun and Earth) are they the greatest?
a. Formed by a combination of gravitational attraction from the moon and sun, as well as the force generated by the earth’s rotation
5. What are the characteristics of a wave and how it breaks on shore and what effects does this have on sediment transport and erosion?
a. Wave refraction: the bending of the waves as they approach the shore at an angle
b. Because of this, wave energy is concentrated against sides and ends of headlands causing coastal erosion. Low energy sites associated with sand deposition (embayment)
c. Wave action
i. Open ocean: waves with constant wavelength
1. Depth is half of wavelength
ii. Approaching shore: waves touch bottom (wavelength shortens) 1. Velocity decreases (wave height increases)
iii. Surf: breakers form
d. Longshore drift: the movement of sediment laterally along a beach; it occurs when waves wash up a beach diagonally
Chapter 16 Main Topics
∙ Groundwater: water that resides under the surface of the earth, mostly in pores and cracks of rock or sediment
o A major component of hydrologic cycles
o A major source of water
o Largely hidden from view but susceptible to contamination o Provides 2/3 of freshwater resources
Drinking water for people and livestock
∙ Karst landscape: a region underlain by caves in limestone bedrock; the collapse of the cave creates a landscape of sinkholes separated by higher topography; or of limestone spires separated by low areas
∙ Water table: the boundary, approximately parallel to the earth’s surface, that separates substrate in which groundwater fills the pores from substrate in which air fills the pores
∙ Unsaturated zone: the region of the subsurface above the water table, pore space may contain some water and some air
∙ Saturated zone: the region below the water table where pore space is filled with water
∙ Aquitard: sediment or rock that does not transmit water easily and therefore retard the motion of water (typically has both low porosity and permeability)
∙ Aquifer: sediment or rock that transmits water easily (high porosity and permeability)
o Confined aquifer: an aquifer that is separated from the earth’s surface by an overlying aquitard
o Unconfined aquifer: an aquifer that intersects the surface of the earth ∙ Groundwater flow
o Gravity and pressure cause groundwater to flow (can flow sideways and upward)
o Infiltrate: seep down into
o Recharge area: a location where water enters the ground and infiltrates down to the water table
o Discharge area: a location where groundwater flows back up to the surface, and may emerge at springs
o Flows from high to low pressure
o Hydraulic head: the potential energy available to drive the flow of a given volume of groundwater at a location; it can be measured as an elevation above a reference
o Very slow compared to surface water
Rate can vary from 4-500 meters per year (13 to 1640 feet per year)
o Groundwater flow rate is a function the slope of the water table (hydraulic head) and the permeability of the material through which the groundwater is flowing
o Moves at a snail’s pace
∙ Cone of depression: the downward pointing cone shaped surface of the water table in a location where the water table is experiencing drawdown because of pumping at the well
∙ Artesian well
o A well in which water rises on its own (due to angled bedrock and natural pressure within the system)
o Potentiometric surface: the elevation to which water in an artesian system would rise if unimpeded; where there are flowing artesian wells, the potentiometric surface lies above ground
∙ Spring: a natural outlet from which groundwater flows onto the ground surface
o Where the ground surface intersects the water table in a discharge area
o Where flowing groundwater collides with a steep, impermeable barrier, and pressure pushes it up to the ground along the barrier
o Where a perched water table intersects the surface of a hill
o Where downward percolating water runs into a relatively impermeable layer and migrates along the top surface of the layer to a hillslope
o Where a network of interconnected fractures channels groundwater to the surface of a hill
∙ Oasis: a verdant (green with grass, etc.) region surrounded by desert, occurring at a place where natural springs provide water to the surface
∙ Hot spring: a spring that emits water ranging in temperature from 30 C to 104 C
∙ Travertine: a rock composed of crystalline calcium carbonate formed by chemical precipitation from groundwater that has seeped out at the ground surface
∙ Groundwater uses
∙ Groundwater concerns
o Over use
o Change of flow direction
o Saltwater intrusion
o Ground subsidence