Unit 4 Flashcards
The hydrosphere
how is the water molecule bonded?
it is covalently bonded which means electrons are shared. The bonds between the molecules results in high surface tension
What is a drainage basin?
two hills or mountains and between them runs a lake or stream, all the precipitation falls between these valleys
What are tributaries?
a stream that feeds inro a large river or lake
What is erosion?
the geological process in which earth materials are worn away and transported by natural forces such as wind and water, The surface of the earth gets worn down
Dendritic drainage pattern
branches like a tree, very common. develops where rock has no structure and is easily eroded
Trellis drainage pattern
generated due to underlying bedrock differential resistance to weathering - associated with folded or faulted sedimentary rocks
rectangular drainage pattern
Generated die to faulted underlying bedrock, low gradient areas (little topography)
Deranged drainage pattern
found in areas with disrupted surface patterns, very chaotic patterns
Radial drainage patterns
formed around isolated mountains
What is the fluvial gradient?
the drop in elevation per unit distance
What is base level?
The lower limit of erosion process (stream has no energy to erode the surface) all streams erode to larger bodies of water
what is local base level
The lowest level of elevation where stream gets water gets stuck for a period of time
Ultimate base level?
the ocean all stream lead will eventually flow into the ocean
What is a graded stream?
a stream that has eroded the bottom of the stream so that its smooth this can be reversed by tectonic uplift or a change in base level
What is the cycle of erosion
youthful stage (stream erodes quickly v-shaped valleys, ungraded streams). Mature stage (streams erode wider broader valleys, deposit thick layers of sediment, gradients slowly reduced). Old stage (streams surrounded by rolling hills (Low gradient) occur wide sediment- filled valleys , gradients are slowly reduced)
Why is stream velocity not uniform?
slowest near the edges and bottom, fastest near the surface and middle depending on shape
stream velocity in curved streams
water flows fastest on the outside curve, slower flow in the inside of the curve
How can particles be transported?
traction transport (bed load) , salation (Bed load), suspension, solution
What is bed load?
large particles that rest on the stream basem only moved during rapid flow, moved through traction and saltation
Traction transport?
sediment pushed along by force of water flow , large particles move slower
saltation transport
bouncing of sediment along stream bed
suspension transportation?
sedimentation held in the water, typically small, higher velocity required for larger particles
Solution transportation?
dissolved ion in the water
Braided rivers
develope when there is more sediment than a stream can carry, Many of interconnecting channels separated by small temporary islands
Meandering stream?
Develop in low gradient areas, one long stream that curves a lot
Point bar vs Cut bank in meandering streams
point bar (sediment accumulates on the inside of the bend)
Oxbow lake?
u shaped lake that eventually cuts off into one line
Deltas
The point where a stream enters a body of water
What is groundwater?
The water found underground and cracks and spaces in soil, sand, and rocks
What are Aquapher?
Aquifer our units of porous rock or sediment saturated with groundwater. It’s made from materials with high porosity and permeability. This is where earth groundwater is stored.
What is porosity (pore space)?
Percentage of open space within a sediment or rock
What is permeability?
Describes how pores and pore spaces are shaped and interconnected
What does larger pores mean?
Less friction between water and the sides of the pores, straighter flow paths and more permeability
What does immobile water mean?
Basically, it’s just stuck water
What are Aquapher?
Unit of porous rock or sediment saturated with groundwater that has sufficient permeability to allow water to flow through it. They are made out of materials with high porosity and permeability.
What is the unsaturated zone?
The poor space is not fully saturated with water. There is air between the pores.
What is a water table?
The boundary between unsaturated ground above, and fully saturated ground below
What is primary porosity?
Porosity presented in spaces between individual sediment grains
What is secondary porosity?
Porosity that has developed after a rock is formed like fractured rocks
What is an acquitard?
This is sediment or rocky body that does not allow the flow of a significant amount of H2O. It’s made from materials with low permeability
What is an aquiclude?
Sediment or rock body, that does not allow any flow of H2O and impermeable unit
What is an unconfined aquifer?
Aquifer exposed to the ground surface, no low permeability barrier between the aquifer and ground surface. The top boundary is the water table.
What is a confined aquifer?
Aquifer has low permeability layer between it, and the water table above
What is the confining layer?
The aqua tired or low permeability layer that separates the water table from the aquifer below
What is infiltration?
Water from precipitation that infiltrates (penetrates) the ground surface. Stored in the unsaturated zone.
How does water flow from recharge to discharge areas?
It’s driven by gravitational forces as well as water travels from high pressure to low pressure. This is called the hydraulic head.
What are springs?
A point where groundwater flows naturally to the surface
Why do whales have to be drilled deeper than the existing water table?
Because the water table fluctuates overtime, and as the water is pumped, the surrounding water table will drop
What is an artesian well?
Water that rises above an aquifer