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
What is karst?
Irregular topography, created by the dissolution of limestone bedrock by flowing groundwater
What are the five oceans?
Atlantic ocean, Pacific Ocean, Indian Ocean, arctic ocean, southern ocean
What is the maximum depth in the ocean?
11 K M, in the Mariana trench
What is the littoral zone?
The shore part of the ocean it’s affected by ties (intertidal zone)
Neritic zone?
From the low tide, Mark to the edge of the continental shelf
Oceanic zone
From zone beyond the shelf
Pelagic zone?
The body of water from just above the ocean floor to the surface
Benthic zone
The ocean floor sediments
Photic zone
Depth through which light penetrates
Aphotic zone
Water depth where sunlight does not reach
Why are ocean salty?
What are supplied to the ocean from rivers of land, these rivers contain dissolved ions. The water leaves through evaporation with no dissolved island. This is what causes the ocean become salty. The reason it doesn’t become over salty is because of salt deposits.
How does the ocean temperature change with water depth
Temperature decreases with depth. This is also called the thermocline.
How does ocean salinity vary with water depth?
Salinity increases with depth, this is called the halocline
How does water density change with depth?
What are density increases? This is called PYCNOCLINE
What are deep current driven by?
Density differences which are caused by salinity and temperature changes along with thermohaline currents
What drives surface current?
Surface wind caused by the chore, Alicis effect 
What is the tidal cycle?
Flows from high tide to low tide as the moon pulls the tidal bulge
What is the tidal period?
The time between two high tides
What is title range?
The difference in height between high tide and low tide largest during spring tides
What is diurnal tide?
One high tide and one low tide per day only one complete title cycle each day
What is semi diurnal tide?
Too high tide and low tides per day to complete tidal cycles each day
What is wave size affected by?
The strength of the wind, the length of time the wind blows for the size of the area the wind blows over
What is fetch?
When wind blows over a body of water with no obstruction in the same direction often causing winds
What is the crest?
The highest surface part of a wave
What is a trough?
The lowest surface part of a wave
What is wavelength?
The horizontal distance between two crests or two troughs
What are wave orbitals?
Circular motion, propagates, downwards, losing energy each time
What is wave base?
The maximum debt at which waters wave movement causes significant water motion
What is longshore current?
Waves approach the shore at an angle it pushes water parallel to the shoreline, this creates swash and backwash. (Swash going towards the shore, and backwash coming to the ocean
What is longshore drift?
The erosion and transportation of sediment along a coastal parallel to the shoreline. This is the result of swash and backwash.
What are rip currents?
Localized currents that flow perpendicular to the shoreline towards the ocean, fed by long shore currents
What are terrigenous sediments?
They are derived from land, and they distributed within the ocean by ocean currents. They include things like sand, silt, and clay. Corser grain cinnamons are deposited closer to shore, whereas small particles travel further into the ocean.
How do beaches form?
An accumulation of sediment it’s a narrow strip of land separating the ocean from inland areas
How do spits form
They developed from an accumulation of sediment provided by longshore drift, and there’s a narrow strip of sediment that extends into water in the direction of longshore current
How do barrier bars exist?
They develop when an accumulation of sediment provided by longshore drift, cuts off a sheltered area, like a bay. Create a narrow strip of sediment that extends into open water in the direction of long shore current, and creates a lagoon where the sheltered water is.
What is pelagic ooze?
Composed of microscopic, silicas and carbonate shells derived from marine organisms
What is the carbonaceous ooze?
Carbonate sediment, derived from marine organisms
What is submergence?
This is the drowning of the land with ocean water
What does emergence
This is the exposure of land once below water
What does global sea level change relate to
Changing volume of global glacier ice
What does global sea level change relate to
Changes to the shape of the seafloor caused by plate tectonic process
What are isostatic sea level changes due to
They caused by the subsidence or uplift of the earths crust, caused by the changes to the amount of ice on land, and or growth or erosion of mountains
What is tectonic sea level change?
Caused by tectonic processes, areas of tectonic, uplift, cause an apparent drop in local, sea level sea level doesn’t actually change, but appears to be lower because the land surface has lifted
What is a glacier?
A long lasting body of ice greater than 10 years that is large enough to move under its own weight
What is the cryosphere?
The portion of earth surface water that is in solid form. This includes sea ice, glaciers, snow, and Perma frost. It plays an important role in feedback, cycles and influences cloud, formation, and precipitation.
How does a glacier form?
Snow accumulates strain winter that does not melt in summer, unmelted snow layer from each year compacted from the overlying weight snowflakes turn into ice granules individual ice granules, continue to undergo compaction and turn into firn (granular snow that is not been compressed into ice) more compaction leads to the elimination of remaining air between individual ice granules. The granules are now welded together.
Plastic lower ice
Flows like viscous fluid, can flow over topography and around bends without breaking
Ridged upper ice
Is brittle and cannot flow will break upon movement will also crack at locations were plastic ice below flexes this leads to the formation of surface crevices
Ice flow at base of glacier if base is cold
Base of glacier is frozen to the rock below, All ice movement is from internal flow base moves very slowly, if at all
Ice flow at base of glacier if base is warm
Base of glacier is detached from the rock surface, a thin layer of liquid between the ground surface, and the glacier, bass slides over top of the ground surface. This is called basal sliding
How do you get a warm glacier base?
Ice axe as an insulator, which can trap heat heat, also radiates upwards from the earth surface. If the ice is thick, he is trapped in the basement melts. If the ice is thin, heat escapes, and the base remains frozen.
How does a glacier flow?
Sides of glacier are more affected by friction than center, so it moves in an arrow shape almost
What is ablation?
Processes that reduce a glaciers mass, which includes melting and calving which is shedding of iceberg into water
What are Alpine glaciers?
Originate on mountains in temperate and polar regions they can form in little latitudes if the elevation is high enough flow is controlled by topography
What are continental glaciers?
Cover vast areas of land in polar regions
How do continental glaciers move?
form on large generally flat areas of land (no slope to help them flow)
Abrasion
As a glacier flows it drags rock, sediment, and debris along its basal surface
Plucking
Bits of underlying rock picked up by flowing glacier
What causes U shaped valleys?
Valleys carved into U shapes by glacier erosion, glaciers erode more along their base than side
Glacial Sediments
Glacier flow is laminar, it doesn’t sort the sediment it picks up.
Glacier Till
The unsorted sediment deposited by a glacier, reservoirs for ground water
Formation of a glacial sediment
Glaciers erode and transport rock as they flow, the debris and sediment is transported on top of the ice, within the ice,
Sub-glacial
below the ice
Supra-glacial
on top of the ice
en-glacial
within the ice
Terminal Moraine
marks the furthest advance of a glacier
Recessional moraine
Marks the retreat of a glacier (The new end)
Glacial Moraines
accumulation of till at the edge of a glacier
lateral Moraines
form along the sides of glaciers
Medial Moraine
When two adjacent glaciers merge lateral moraines
Eskers?
linear accumulations of till parallel to a glaciers movement, form from deposition of a sediment from river flowing beneath a glacier, subglacial
Drumlins
accumulations of till in tear drop shapes parallel to a glaciers movement
Erratics
glacially deposited rock differing from the bedrock of the area - transported on or within the ice
Kettle Lakes
Lakes formed from the melting of remnant glacial ice blocks
