GPH
Terms
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- the study of water is called _____.
- hydrology
- evapotranspiration occurs in three areas:
-
ground
plants
atmosphere - the path water takes in our environment is called the
- hydrological cycle
- storage refers to
- soil and/or ground water
- an underground rock layer that holds water is called an ____.
- aquifer
- what is an aquifer?
- an undergroudn rock layer that holds water
- precipitation-evaporation (movement of water across the surface of the Earth is called
- runoff
- runoffs go into
- rivers and streams
- is an underground lake an aquifer?
- no
- amount of runoff in rivers and streams is called
- discharge
- discharge
- amt of runoff in rivers and streams
- equation for discharge
- cross section area (widthXdepth) * velocity
- River flows at 30 mph. Depth of river is 5 feet & Width is 10 feet. What is the Discharge?
-
Cross-Section = 5 feet X 10 feet = 50 square feet. Velocity is 30 x 1.5 = 45 feet / sec
Discharge would be 50 square feet x 45 feet / sec = 225 cubic feet /sec or 225 cfs - Rate of discharge depends on
- Gradient (the difference in the elevation of the upstream point minus the elevation of the downstream point /distance between the two points: the larger the gradient the greater the discharge)
- Drainage basin
- land area that contriubtes runoff to river system
- Drainage divide
- boundary between drainage basins (the higher elevations)
- Drainage or Stream Network
-
1. The system of the main river channel plus its tributaries
2. Stream network: hierarchical (ranking) system - Baseflow:
- Groundwater runoff released over large periods of time (the average flow of the stream)
- Stormflow:
- Overland flow (the extra water running off land from a storm)
- Stream Hydrograph
- plot flow against time
- What influences the shape of hydrography
-
a. Size of basin
b. Type of surface
c. Shape of watershed
d. Slope
e. Intensity & duration of rain - Urbanization
- Pavement and concrete are impermeable to water so water must flow across surface
- do rural or urban floods occur faster?
- urban
- Fluvial Landforms
- Landforms created by running water
- __________ have done more to shape our earth than any other process
- fluvial processes
- Erosion
- the wearing away of land and soil though the process of running water
- gully created by
- fluvial processes
- arroyos created by
- fluvial process (running water)
- gullys formed by
- erosion (fluvial)
- arroys formed by
- erosion (fluvial)
- deposition
- the placement of the material carried by running water
- deltas created by
- deposition (fluvial)
- Types of erosion
-
splash erosion
accelerated erosion - Splash erosion
- direct force of falling drops on base soil causing a geyserlike splashing in which soil particles are lifted and then dropped into new positions
- Accelerated erosion
- the removal of soil much faster than it can be formed
- Example: Badlands
- fluvial (accelerated erosion)
- 3 mechanisms of Stream Geology
-
Stream erosion
Stream transportation
Stream deposition - Stream Erosion
- Removal of material from the floor and sides of a channel
- Stream Transporation
- movement of the eroded particles
-
Stream Geology
3 mechanisms -
stream erosion
" transportation
" deposition - 3 mechanisms of stream transportation (movement of particles)
-
suspension
dissolved
bedload - Suspension
- Material is held up by the water in the stream
- Dissolved:
- Material is mixed with the water
- Bed Load
- sand, gravel and cobbles move by rolling or sliding from water flow
- Saltation
- bouncing or skipping along stream bed
- Traction
- : rolling or sliding
- 2 types of bedload
-
saltation
traction - Stream Deposition:
- depositing the material carried by the stream
- Stream Gradiation:
- The SLOW reduction in the height of the headwaters of a stream through time as the stream eroded away the surrounding materials.
- waterfalls aka
- knickpoints
- flood plain
- belt of low flat ground present on one or both sides of a stream channel and is the area subject to flooding by that stream
- thalweg
- deepest and fastest moving water in the river (usually at side of river)
- cutbanks
- areas where fast moving water erodes away at the side of the river (outer banks)
- sandbars
- areas oppositve of cutbanks..areas of deposition due to slow moving water.
- oxbow lakes result from
- fluvial processes (erosion)
- 2 types of streams
- meandering braided
- Sandbars & Cutbanks continually reshape the river, causing it to create bigger and bigger meander loops. Eventually, we have the formation of
- ox-bow lakes.
- Example: Near Omaha Nebraska, "Crescent Lake, Iowa"
- oxbow lake -- fluvial process
- Eventually, the ox-bow lake dries up (it is no longer linked to the river) and becomes a marshy swamp called
- "a meander scar."
- Meandering stream.
- The river has only one main channel that wanders (or meanders ) from side to side of the floodplain.
- Rivers in the Eastern US (and ms river) is an exampel of a
- meandering stream
- Braided stream
- the flow is divided into multiple threads and these rejoin and subdivide as new sandbars within the river form
- western us rivers
- braided streams, very shallow
- Deltas
- Deposition of material dropped at the river mouth
- : Sea Level has rised 400' in the last 10,000 years. Why?
- Reason: Melting of Laurentide and Scandinavian ice sheets
- Tides: What are they?
- 1. Daily changes in sea level. In a normal day, we experience two periods of rising water (flood tides) and 2 periods of falling water (ebb tides).
- Two forces cause tides:
- a) gravitational attraction of moon and to a much lesser extent the gravitational attraction of the sun. b) centrifugal force (the earth's spin pulls water away)
- Biggest Tide:
- Springtide: moon and sun are aligned so their gravities act together and so the sea rise is much higher
- Tidal Waves ARE/ARE NOT caused by tides.
- ARE NOT They are caused by undersea earthquakes. Better name is TSUNAMI
- Waves Caused by
- winds moving over a water surface.
- Swell:
- low, round-crested linear waves
- Fetch:
- the area over which winds build waves: The bigger the fetch, the bigger the waves.
- Collapsing Breaker:
- the base of the wave collapses and the wave crashes into a mass of foam. Unrideable.
- Spilling breaker:
- the crest (top) of the wave slides down the front of the wave. Rideable but not much action.
- Plunging breaker:
- the crest shoots forward of the base (bottom) of the wave in a smooth curve. The classic surfers' wave!
- Cape Cod Example of
- coastal erosion
- Thick, wedge-shaped deposits of sand along a body of water are called
- beaches
- what is Longshore Current and Beachdrifting
- waves force you to drift bc waves come in at an angle
- New Jersey groins
- manmade barriers to prevent beach erosion
- spit
- beachdrifting and longshore current create an arm of sand across a bay
- Tombolo:
- a spit that ties an island to the mainland
- Barrier Island:
- a narrow strip of sand dunes, beaches, and marshes located a few miles off-shore
- All along the Atlantic coast (Cape Hatteras, North Carolina is one) and along the Texas coast (South Padre Island is one)
- Barrier island -- Barrier Islands were probably the beaches of the land during the Last Ice Age when sea level was much lower than present day. But now because they are generally made of sand, they are eroding away.
- Types of Coral Reefs:
-
A. Fringe Reefs
B. Barrier Reefs
C. Atoll - Fringe Reefs
- are built out from the shore
- Barrier Reefs
- are separated from an island or landmass by an enclosed water area.
- Atoll
- : A reef which has an interior lagoon and needs no land
- #1 element in earths crust
- oxygen
- Mineral:
- chemical compound, inorganic substance with consistent chemical composition (has the same things throughout it)
- Rock:
- minerals grouped together or an aggregate of minerals.
- Most of earth's crust is made up of ____ materials
- silcate minerals (silicon and oxygen)
- Igneous:
- rocks are solidified from mineral matter in a high temperature molten state. Hard.
- granite is an _______ rock
- igneous
- when molten, Igneous rock known as ___. When magma forces its way to surface, it is known as ____.
- magma lava
- Sedimentary rocks:
- layer accumulations of mineral particles derived in various ways from pre-existing rocks. Soft and flaky.
- Sandstone, shale
- sedimentary rock
- Metamorphic:
- igneous or sedimentary rocks that have been physically and chemically changed usually by extreme heat and pressure
-
Limestone + heat/pressure = marble
carbon + heat/pressure = diamond - metamorphic rock
- Crust:
- very thin layer (like onion skin). makes up continents and ocean basins
- crust is divided into 2 layers
-
a. sima or basaltic layer: heavy; only exposed in ocean basins
b. sial or granitic layer: on top of sima. forms continents - the transition between crust and mantle is called
- the Moho
- rock underneath the lithosphere is highly heated to a state that is semiplastic (think of white hot iron that can be shaped and molded), this is called the
- asthenosphere.
- Important idea is that the lithosphere is capable of moving over the
- asthenosphere.
- lithosphere is broken up into large fragments called
- lithospheric plates
- Alfred Wegner, proposed that at one time all continents were fused into 1 continent called
- Pangaea.
- Due to a process he called ... that continent broke apart until gradually the continents drifted into their current positions
- continental drift,
- If two plates of the same density hit (like two continental plates), they
- throw up a huge range of land (mountain building). Prime example of this is the Himalayas
- If two plates of different density (like a continental plate and an oceanic plate), ... The process of downplunging of one plate beneath another is called .. The plate boundary is called .
-
the denser plate (the oceanic plate) is forced down and into the softer asthenosphere.
subduction
Subduction Zone - If two plates are moving away from one another,
- a crack between the two forms and new material is formed
- What causes the plates to move in the first place?
- Convective currents in the asthenosphere. Differential heating causes the movement.
- MidAtlantic Mid-Oceanic ridge formed by
- plates moving apart
- plates moving apart causes
- Shield volcanoes
- typeso f volcanoes
- strato , shield
- . Strato Volcano
-
a. Very explosive, with rocks gases and ash
b. creates high cone, deep steep sides and layered appearance - when a volcano explodes in a violent explosion such that the central portion of the volcano is destroyed, the great central depression that remains is called is called
- a caldera
- Crater Lake, Oregon or the San Francisco Peaks in northern Arizona
- Strato volcano/caldera
- Lahar:
-
Indonesian term for a volcanic-created mudflow.
Combination of three processes: Mass Wasting+Fluvial+Tectonics - Shield Volcanoes
-
groups of fissures or tunnels that are active over a long period of time creating broad mountains
Mostly located in oceanic areas
created by Hot Spots - Hot Spots:
- as a lithospheric plate drifts slowly over a Hot Spot, a succession of shield volcanos is formed. As the plate drifts over the plate, a chain of volcanic islands is formed
- 2 types of lava flow
-
e. Pahoehoe: ropy
f. A’a: sharp, brittle - Lava Tube:
- A long "worm-like" cave that is formed as molten lava flows through a tube formation of older cold hard lava
- east and west sides of the San Francisco Peaks.
- lava tubes
- cheap and efficient portable volcanic observatories.
- US International Volcano Disaster Assistance Program:
- Faulting:
- the result of sudden yielding of the rock under unequal stresses: in essence, when one rock surface moves one way and the surface next to it moves another.
- Fault line:
- the division on the surface between the two different rock surfaces
- Two types of faults
-
1. Normal fault
2. Transcurrent fault - Normal fault
- the plane of slippage is steep or nearly vertical. One rock surface is raised or lowered in relation to the surface next to it.
- Transcurrent fault
- in a transcurrent fault, the movement is not vertical but predominantly horizontal. No scarp results.
- San Andreas Fault is what kind of fault
- transcurrent
- Mongollon rim is what kind of fault?
- normal
- faults are from what kind of process/
- tectonic landforms
- Earthquakes
- a motion of the ground surface
- Safety from earthquakes
-
a. ⬢Inside, stand in doorway, or crouch under a desk or table, well away from windows or glass dividers.
B. ⬢Outside, stand away from buildings, trees, telephones and electrical lines.
c. ⬢On the road, drive away from underpasses and overpasses; stop in safe area; stay in vehicle. - Where do earthquakes occur?
- so-called Ring of Fire around the Pacific Ocean. But also within a continental plate.
- Tsunami
- NOT a tidal wave. Is a huge wave created by an undersea earthquake.
- Geothermal Energy:
- Geysers created by Hot Spots. The heat produced by a hot spot can sometimes be high enough to boil water. If an underground river flows above a hot spot then that river can be heated to the boiling point. If there is a vent to the earth's surface from which the steam can escape, the result is a geyser. Example: "Old Faithful" in Yellowstone National Park in Wyoming.
- Old Faithful example of
- Geothermal energy (geysers)
- The last eruption of a mega-volcano was in Toba
- Toba
- MASS WASTING
- Landforms shaped by mass movement
- Talus slope/cone: created by
- Landslide
- Soil Creep
- very slow movement of soil down a slope
- Earth Flow
- water-filled soil moves downslope
- Bulging toe:
- the landform created by an earth flow
- what is mass wasting?
- the movement of material by gravity
- Energy
- cannot be destroyed but can be transformed from one kind to another
- potential energy
- energy of position -- the higher the position, the higher potential energy
- kinetic energy
-
the energy of motion
the faster the motion, the greater the amt of energy - how is a talus slope created?
- physical weather action taken place on steep cliff area, breaks rock into fragments mainly by frost action, gravity carries rock fragments downslope
- Mud Flow occurs when there is
- 1. More water than Earth Flow
- Mudflows occur in places where
- there is little vegation
- Mudflows are found in
- arid or semiarid areas or in areas subject to forest or wild fires
- south slope of A Mountain example orf
- talus slope
- very slow mass wasting called
- soil creep
- importance of understanding mass wasting
- classic natural hazard: can move in a matter of minutes
- mudflows aka
- debris flow
- mudflows also common in areas of
- volcanic eruptions
- The sequence of how much mass wasting &/or fluvial transport depends on
- how much water is present
- No water -----> All Water
- Landslide Earthflow Mudflow Flash Flood
- a volcanic mudflow
- lahar
- a lahar is a mixture of __, __, and ___ processes
- tectonic, mass wasting, fluvial
- weathering and erosion can be both ___ and ____
- physical and chemical
- physical weathering aka
- freeze/thaw action
- the MacGyver principle
-
physical weathering/freeze thaw
when water freezes it expands. if expansion takes place in the joints spaces of rocks, the rocks themselves breaks apart - when water evaporates frolm cracks, leaving behind salt crystals that grow over time. crystals expand and break up rock letting gravity carry the materal downslope. this is called
- crystallization
- crystallization
- when water evaporates frolm cracks, leaving behind salt crystals that grow over time. crystals expand and break up rock letting gravity carry the materal downslope.
- unloading aka
- pressure release weathering
- unloading
- when rock is deeply buried and subjected to high pressure. pressure is released on surface and rock can break away
- devils tower wyoming is an exaple of
- unloading (weathering)
- when some materials absorb water and expand. known as
- hydration
- hydration
- when minerals absorb water and expand causing rocks to break up
- hydration is an example of
- physical weathering
- cyrstallization is an example of
- physical weathering
- unloading is an example of
- physical weathering
- carbonation and solution is an example of
- chemical weathering
- carbonation and solution
- a mineral dissolving into a solution
- Sedona is an example of
- oxidation
- San Francisco Peaks good example of
- lava tube
- Volcanic Ranking Scale (VEI) numbers
- 0-8
- Aeolian processes:
- Landform changes created by wind
- Two types of Wind Erosion
-
Deflation
Wind Abrasion - dust storm an example of
- deflation (aeolian processes)
- Deflation:
- loose particles lying on the ground are lifted up into the air or rolled along the ground
- Wind Abrasion:
- When wind drives sand and dust particles against exposed rock or soil surface causing it to be worn away by impact of the sand
- Dust storms:
- strong winds lifte huge quantities of fine dust forming a dense low cloud of material.
- A landform produced by deflation is a shallow depression called a .
- blowout
- After deflation has gone on for some time and has blown away the smaller particles, the remains are a solid surface called a
- desert pavement
- Sand dune:
- any hill of loose sand shaped by the wind. Several different kinds of sand dunes exist.
- Crescent (barchan) dune.
- Hill of sand which is quarter-moon or crescent-shaped
- The tips of the crescent point
- downwind
- The steep slope of the leeward (downwind) side of a barchan/crescent sandune is called the
- slipface
- . Barchan dunes form where the winds
- flow consistently from one direction.
- Traverse Dunes:
- long ridges of sand separated by long troughs or valleys of sand.
- Traverse Dunes are related to Barchan dunes because their tips blow
- downwind
- Traverse Dunes tend to form in areas with
- abundant sand > large areas of sand ("sand seas") are called ergs.
- abundant sand > large areas of sand ("sand seas") are called
- ergs.
- The central Sahara
- . Traverse Dunes
- A type of Dune that occurs in semiarid rather than arid areas is called a
- Parabolic Dune.
- Parabolic Dune Usually found behind
- blowouts.
- the points of the parabolic point
- upwind
- limestone gravestone dissolving good example of
- carbonation and solution
- turquoise an example of
- hydrolosis
- Seif or Longitudinal Dune
- is a long narrow ridge oriented parallel to the direction of the prevailing wind.
- the Sandhills of Nebraska.
- Seif or longitudinal dune
- Star Dunes:
- these are huge dune mountains that are found in large erg ("sandsea") deserts.They are sand mountains that can be as much as 600-700 foot high. Star Dunes are fixed in position (don't move) and seem to require wind blowing from many different directions to form.
- In a few extremely dry (arid) areas, strong winds have eroded long parallel grooves in the solft silts of old dried-up lake beds These ridges are called
- yardangs.
- desertification):
- Man-Made deserts ( plowing land that experiences wide variations in precipitation can lead to deflation and the land becoming a desert).
- A glacier is
- any body of flowing ice that has been formed on land by compaction and re-crystallization of ice
- Two Types of glaciers
-
1. Continental
2. Alpine or mountain - Today only two continental icesheets exist:
-
1. Greenland
2. Antarctica - During the Pleistocene (remember, it's the last ice age), there were two more ice sheets:
-
1. Laurentide Ice Sheet (N. America)
2. Scandinavian Ice Sheet (N. Europe - alpien or continental glaciers smaller?
- alpine
- alpine glaciers found in
- higher altitudes
- Three types of alpine glaciers
-
1. Cirque Glacier:
2. Valley Glacier:
3. Piedmont Glacier: - Cirque Glacier:
- Glacier found near the top of the mountain on the sdie of the mountain. The glacier craves out a bowl-like depression in the side of the mountains.
- Valley Glacier:
- a glacier that extends down the mountains from the cirque glacier down the mountains.
- Piedmont Glacier:
- a glacier that extends from the valley glacier into the area around the mountain.
- Néve
- is a general term for all compacted snow ... a transition between snow and glacial ice
- Fírn
- is a specific term for néve that does not melt.
- Ablation:
- the zone of melting on a glacier
- Accumulation:
- the zone of nonmelting snow on a glacier, the region where snow is added to a glacier.
- If zone of accumulation is larger than ablation, the glacier , if ablation is larger than accumulations, the glacier .
-
advances
retreats - Cirque:
- The bowl-like depression that is carved by a glacier. Cirques are high up in the mtns. surrounded by high sheer cliffs.
- Bergschrund:
- the crack between the glacier and the mountains. Dangerous: it is often covered by a thin layer of snow.
- Crevasses:
- As a glacier flows down a mountains, it reaches areas where elevation suddently drops. Ice will not flow down these drops but instead it breaks into deep crevasses and ice falls.
-
Glaciers move because
Which part of a glacier moves the fastest? -
the weight of the ice and gravity pull them down the mountain or across the land.
The center moves fastest because the sides and bottom of a glacier are sliding against rock and therefore friction slows down those parts of a glacier down. - Two methods of glacial erosion.
-
F. Glacial Abrasion
G. Glacial Plucking - Glacial Abrasion:
- As rock and ice carried by glacier, they scrape and grind against surrounding rock and wear it away.
- Glacial Plucking:
- glacier forces rock fragments to be lifted out of surrounding rock by freezing water in cracks and surrounding rock. Cracks expand and the rock fragment "pops" out of the surrounding rock and is carried down the mountain by the ice.
- What happens to rocks that are carried by glacier?
- Moraine: Debris carried and deposited by glacier. Often appears as small hills or ridges after glacier has melted awway.
- Three types of alpine (mountain) moraines
-
1. Lateral: material carried and deposited by glaciers on sides of glacier.
2. Medial: debris created by 2 lateral moraines merging: the debris is located in middle of a new glacier.
3. Terminal debris is pushed and left in front of the glacier - Aréte:
- Formed when 2 cirque glaciers on opposite sides of mountain cut away the mountains, leaving a sharp ridge between the two cirques
- Horn:
- when 3 or more cirques intersect (or three or more arétes intersect), you get a "horn".
- . Glacial Trough:
- a huge "U"-shaped valley carved by a glacier
- When a glacial trough fills with sea water, we call it a
- Fjord
- A river valley tends to be a __ shaped while a glacial trough tends to cut a ___ shaped valley
-
"V"
"U"-- - When a cirque glacier melts, it generally leaves a small lake in the cirque depression. This lake is called a
- "tarn lake
- What happens to the land when it is under that much ice?
- The land sinks!
- Isostatic depression:
- The weight of ice is so great that the land is depressed sometimes to the point of being below sea level.
- Hudson Bay ex of
- isostatic depression
- Ice Shelf:
- A large plate of moving ice that has slid out on top of the ocean. Can be hundreds of feet thick.Example: Ross Ice Shelf in Antarctica
- Sea Ice:
- Ice formed directly on ocean by freezing ocean water
- Iceberg:
- Formed by pieces breaking off ("calving") continental glaciers and falling into ocean.
- Meltwater stream.
- A river created by water from melting ice from a glacier
-
Great Lakes and St. Lawrence Seaway
B. Rivers in the Central United States
landforms from what? - Glaciers
- Moraines: Just as with alpine glaciers, continental glaciers have moraines. However, continental glaciers are so big that they don't
- have sides and thus only have terminal moraines composed of the rubble and debris carried ahead of the glacier
- the shape of continental moraines are huge curved paths called
- "lobes
- When two lobes of a continental glacier come together, they form an "
- interlobate" moraine.
- If, as the continental glacier is retreating, the glacier stops or actually starts advancing slightly, a smaller moraine forms behind the terminal moraine. This moraine is called a
- recessional moraine.
- After a glacier is gone, the moraine appears as a belt of knobby hills separated by small hollows. The hills are called "". The hollows often fill with water and the resulting lake is called a "".
-
knobs
kettle lake