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Running Water
1) The Hydrologic Cycle:
 The circulation of water between the hydrosphere,
solid earth, and atmosphere.
 Powered by the sun
 97% of the Earth’s water is in the ocean
2) Streams and rivers
Water is sourced mainly from groundwater and surface
runoff
a) Surface runoff
 Drainage Basins: an AREA that collects water to supply
streams
 Drainage Divides: high places that separate drainage
basins
 Longitude Profiles: shows slope, view from head to
mouth
b) Base level and graded streams
Two general types of base level
 Ultimate: the ocean
 Local/temporary: waterfall, dam
 Raising base level causes deposition
 Lowering base level causes erosion
Graded Streams:
 Maintain the exact velocity required to transport
materials and neither erode or deposit.
 A natural state for streams
c) Transport of Sediment by Streams
Capacity amount of material a stream can carry
Competence the largest size material that is carried
Dissolved load

Material dissolved in the water

Supplied mostly by groundwater
Suspended load

Carries largest amount

Sand, silt, and clay

Velocity decides what size material will be carried and
what will be deposited
Bed load

Largest material

Bounces along the bottom

Only moves when water is forceful
d) Deposition of Sediment by Streams
Stream sediments
 Generally well sorted
 Stream sediments are known as alluvium
 Velocity separates the particles by size (sorting)
 Bars: sand and gravel deposited in a channel.
Alluvial fans:
 Intermittent streams depositing large amounts of
sediment onto a valley floor in the shape of a fan
 Common in deserts
Deltas:
 Formed when a stream or river enters a body of water
with lower energy, and deposit its sediments
 Can produce large volumes of coarse sediment
 Great Oil and Gas Reservoirs
Ex: Gulf of Mexico
Floodplains:
 Valleys that flood from meandering streams
 Consist of silt, sand and gravel
 Large flat areas plains with multiple old stream channels
 Sediment deposited during the formation of floodplains
create natural levees
e) Stream Valleys
Narrow V-shaped: Niagara Falls
 Higher gradient
 Farther from base level
 Rapid down-cutting in resistant rocks
 Rapids and waterfalls (young features) are common
 Vertical walls
 More vertical erosion
Wide valleys: meandering streams like Miss. River
 Lower gradients
 Closer to base level
 Mostly in a single channel with few islands
 Has raised edges called levees.
 More forceful side to side meandering
 Meandering streams flow on floodplains
 Terraces form when river has adjusted to a relative drop
in base level by downcutting
Point bars: deposition on inside edge of meander
Cut banks: outside edge of meander-erosion
Cutoff meander: cut through a meander and connect with
another part of the stream
Oxbow lake: An abandoned meander, it eventually fills
with sediment and becomes a meander scar.
f) Stream Process and Response
i) Uplift of land/Elevation of mouth falls
 Increases gradient and stream flow
 Stream starts to erode: both headward and downward to
bedrock
 Stream terraces: create new floodplain level
 Stream piracy: erosion into current channel and steals its
flow.
ii) Elevation of mouth rises
 Decreases gradient and stream flow
 The stream starts to drop sediment in its channels and
on floodplain during floods
 Results in wide flat-floored floodplain valleys
Groundwater
 One of the most valuable resources
 About 1% of freshwater is underground
 Largest supply of freshwater
1) Distribution of Underground water
 Groundwater generally accumulates in sedimentary
basins
 It flows in response to gravity
 It moves very slowly, feet per year
 It is easily contaminated and difficult to cleanup
2) The Water Table
Zone of Aeration
 Area above the water table
 Lots of water, but hard to collect because of how it
attaches to rocks and soil
Zone of Saturation
 Below top of water table
 Completely saturated
 Varies seasonally due the quantity, distribution, and
timing of precipitation
 Streams interact with the groundwater system
Gaining streams
 Streams that gain water from groundwater
Losing streams
 Streams that lose water to groundwater
3) The Storage and Movement of Groundwater
Porosity
 Percentage of void space in rock and sediment
 Stores fluid
Permeability
 The ability to transmit water through the pores of
sediment or material
Aquitards
 The layers of material that prevent water flow
Aquifers
 Sediments or material that transmits water freely
a) Movement of Groundwater
 Very slow
 Its caused by gravity
 It moves from high water table zones to low zones
Springs
 Where the water table meets the Earth’s surface
Wells
 Most common way of retrieving GW
 Used for agriculture, and drinking water
 Wells must break through the water table
 When the water table is lowered away from the well, its
called drawdown; this results in a cone of depression
Artesian Wells
 Wells that flow to the surface
 Water rises above the top of the aquifer
 An aquitard must both be present
Hot Springs
 Hot Springs that have a much warmer water temp than
local air temp.
 Water is heated by circulating deep in the Earth
4) Problems Associated with Groundwater
Withdrawal
 Water table height is effected by amount of water going
into and coming out of aquifer
 Severe droughts and over usage of wells can cause long
term decreases in water table height
 Subsidence: GW removed more that replaced, it can
cause the ground to sink
GW contamination and cleanup
 Point or non-point sources
 Subsurface mobility of chemicals
 Toxicity of chemicals: how are levels determined?
Glaciers
 Form when more water is frozen than melts each year
 Water is stored in glaciers for long periods of time
 2% of the earth’s water is in glaciers
 If all glaciers melted, sea level would dramatically rise
 Glaciers are a strong erosional force, like a bulldozer
1) Types of Glaciers
a) Valley (alpine) glaciers
 Slow moving glaciers located in old stream valleys
 Ice bound by rock walls that flow from an upward point
 These form many features of classic glacier landforms
b) Ice sheets
 Much larger than valley glaciers
 Two currently exist N. Pole/Greenland and Antartica
 Flow into ice shelves: flat masses of ice that extend
toward the sea
c) Other types of glaciers
Ice caps
 Small ice sheet glaciers, that cover upland and plateaus
and bury landscape
Outlet glaciers
 Flow from ice caps and ice sheets outward through
mountains toward the sea. Like localized valley glaciers
dumping into sea
Piedmont glaciers
 When valley glaciers merge at base of large mountains
2) Movement of a Glacier
a) Two types of flow
Plastic flow
 Movement within ice
Basal slip
 Mass of ice slips along ground
 Melted water causes ice to move over rock
 Caused by heat from in the earth
b) Zone of Fracture
 Does not flow, is brittle and cracks
 Forms crevasses from glacier moving over rough terrain
c) Rate
 Some glaciers move at unnoticeable rates (cm/day),
while others move up to several meters a day
 Quick movements by glaciers are called surges
d) Zone of Accumulation
 Area defined above the snowline
 Where ice and snow collect and form
e) Zone of Wastage
 Located generally below snowline
 Where glaciers lose ice and snow due to melting
 Ice can break off in a process called calving which
produces icebergs
f) Glacial budget
 Balance between zone of wastage and accumulation
 If budget is positive glacier grows, if not glacier shrinks
3) Glacial Erosion
a) Plucking
 Water flows into cracks of rocks and freezes
 Glacier lifts, picks up and moves rocks
 Can move very large rocks
b) Abrasion
 Caused by rock movement sliding over rock, “sanding”
it down
 Produces rock flour and glacial striations
4) Landforms created by Glaciers
 Glacial regions have U-shaped valleys with steep slopes
 Glaciers generally flow along previously existing
streams
Glacial trough: U-shaped valley
Hanging Valleys: Above a glacial trough, after glaciers
move away.
Truncated spurs: Triangular shape, where a ridge meets a
glacial valley
Pater noster lakes: String of lakes formed after glacial
retreat in a glacial trough. Created by plucking.
Cirque: Bowl shaped, terminal head of glacier valley
Tarn: Small lake located at base of cirque, created from
plucking.
Fiords: Steep sided inlets in the sea. Caused from
submerged glacial troughs and sea level rising
Aretes: Sharp sided ridges that line glacial valley.
Horns: Cirques grouped around a point. Sharp pyramid
shaped peaks (Like Matterhorn at Disneyland).
5) Glacial Deposits
Glacial Drift:
The sediments deposited by glaciers.
Two types: Till and Stratified drift
a) Glacial Till
 Sediment deposited when ice melts.
 Melting ice can’t sort sediments.
 Characterized by very poorly sorted, polished and
scratched sediments.
Moraines
Lateral moraine:
 Ridge formed by till on outside edge of glacier
Medial moraine:
 Formed by two lateral moraines when glaciers merge
together
End moraine:
 Ridge of till that marks the former spot of the front of a
glacier.
Ground moraine:
 Layers of till in areas where ice moves away
Drumlins:
 Elongate parallel hills covered by ice sheets
 Composed of till, found in groups, or drumlin fields
Glacial Erratic:
 Large rocks or boulders free lying that originate from
elsewhere
b) Stratified Drift
 Sorted from glacial melt water according to shape and
size
 Layered and better sorted than till
 Consists mostly of sand and gravel
i) Outwash plain
 Large sloping surface created near the edge of end
moraines
 Called a valley train when limited to a valley
ii) Ice-contact deposits
 Sediment deposited underneath melting ice by melt
water
Kames:
 Hills created underneath melting ice by melt water
Eskers
 Large ridges of sediment following streams underneath
melting ice by melt water
6) Glacial Theory and the Ice Age
 Last ice age was about 18,000 years ago
 Climate changes come from variations in the earth’s
orbit and tilt of the axis
Deserts
30% of earth’s land is made up of dry regions
1) Two dry land types
Deserts
 Lacks water
 Very dry
 Generally defined as less than 10” of precipitation per
year
Steppe
 More humid, semiarid
 Transition between desert and more moist areas
 Acts as a border area between desert and other climates,
can be from a rain shadow.
a) Low latitude deserts (30 degrees N and S of EQ)
 Near Tropic of Cancer and Capricorn
 High pressure and wind circulation are responsible for
dry climate
b) Middle latitude deserts
 Far from ocean
 Mountains around keep moisturized air away
 Can be from a rains shadow
 Area resulting in less moisture and cloud formation
2) Geologic Processes in Arid Climates
 Mostly mechanical weathering
Waters role in deserts
 Water is responsible for most desert erosion
 Contain ephemeral streams, only flow after heavy
rainfall
 Floods more common because lack of vegetation and
dryness prevent water from soaking into the land
3) Transportation of Sediment by Wind
 Different from water
 Density of wind is lower than water
 Wind spreads over large areas, not just channels
Bed load
 Mostly sand
 Moves (skips) along surface through a process called
saltation
Suspended load
 Made up of silt and clay
 Can be carried much farther and higher into the
atmosphere
a) Wind Erosion
 Deflation
 Lifts and removes loose material
 Create blowouts
 Layer of pebbles and small rocks that are too large to
be moved by the wind is called desert pavement
Abrasion
 Wind sands down rocks
 Creates uniquely shaped rocks called ventifacts
 Ventifacts are rocks that are polished and shaped by
wind
4) Wind Deposits
Dunes
 Sand deposited in the shape of a mound or ridge
 Slope on the sheltered side is very steep; windward side
has a gentler slope
 Layers that form on the steep side are called cross beds
Types of sand dunes
Barchan
 Solitary, U-shaped with tips pointing downwind
 Form where there is limited sand, flat with little
vegetation
Transverse
 Long ridges perpendicular to wind
 Largest dunes: up to 200m high, 1-3 km across, 100’s of
km long
 Steady wind lots of sand and little vegetation
Longitudinal
 Long ridges parallel to wind
 Up to 100m high, can be 100’s of km long.
 Moderate sand with changing winds
Star
 Variable wind, star shaped.
5) Terms:
 Bajada: coalescence of alluvial fans at base of a
mountain
 Playas: flat central area of an undrained basin
 Playa lakes: temporary lake in playa
 Inselbergs: isolated mountain peaks from late stage
erosion in a desert
Shorelines
 Boundary where different systems interact together
 Waves and currents change the features of the coastline
 Moves and deposits sediment along coast
 Coastal landforms are delicate, short-lived features
1) Waves
Terms
 Crest: top of wave
 Trough: separates crests
 Wavelength: horizontal distance between crests
 Period: time between crests
 Wave height: measured between crest and trough
Wave period and wave energy
 Longer wave periods have much higher energy and
higher open ocean velocities
 Stronger, longer duration storms produce longer period
waves.
2) Longshore Transport
 When waves meet the shore at an angle
 Transports sediment in a zigzag pattern along the beach
with longshore current
 Longshore transport can move large amounts of sand
along the shoreline
 In San Diego its strongly to the south in the winter and
slightly north in the summer
3) Shoreline Features
a) Erosional
Wave-cut sea cliffs
 Sea cliffs form along the shoreline from wave erosion
 With time sea cliffs migrate landward and grow in size
Wave cut platforms
 Slightly seaward sloping surface cut in surfzone
 These become uplifted and exposed on emergent
shorelines
 Common in San Diego and on the California Coast
Sea arch
 Form at headlands where 2 sea caves that come together
from different sides
 Perforate through headland
Sea stack
 Form when a sea arch fails
 Mound of rock and debris that eventually is taken to
sea by waves
 Common on the West Coast
b) Depositional
Spits
 A deposit of sediment normally formed from longshore
current deposition where the water goes from high
energy to low energy
Ex: Santa Barbara Harbor
Bay-mouth bar
 A sandbar that stretches across a bay, separating it from
the ocean
Tombolo
 A low energy zone is created by a structure, and island,
a breakwall etc. and sediment get deposited behind it.
Barrier islands
 Ridges of sand that run parallel to the coast
 Common on submergent coasts
Ex: East Coast
4) Shoreline Erosion Problems
 Most erosion occurs during storms with larger longer
period waves
 Large waves break against rocks and sea cliffs, etc.
 The waves undercut cliff and it fails
 Rock fall if the rocks are hard and cliffs are near vertical
 Slump if the sediments are soft and sloping
Types of shoreline protection
Breakwaters
 Structures used to protect boats from large waves.
 Protects and builds beach in front of breakwall
Seawalls
 Seawalls are built up against sea cliffs to protect land
structures and sea cliffs from large waves.
Beach nourishment
 Adds large amounts of sand to the beach to keep water
away from sea cliffs
 Raises beach sand level
Jetties and groins
 Are used to trap and buildup sand
 Increases deposition on upcurrent side and increases
erosion on downcurrent side
5) Emergent and Submergent Coasts
Another important factor in understanding shorelines is
tectonic activity
A) Submergent
 Sea level rises or land sinks down
 Contain estuaries and barrier islands
 East Coast is an example
B) Emergent
 Land rises or sea level drops
 Forms marine terraces, sea cliffs, and sea caves
 California is an example
6) Tides
 Daily change in ocean elevation
 From gravitational attraction of the moon and sun
 Spring tides create the largest range during new/ and
full moons
 Neap tides create a smallest tidal range, during 1st and
3rd quarters moons
7) Tsunamis
 Formed by rapid displacement of seawater from an
earthquake, landslide (or underwater), or volcano.
 Usually less than 2 feet in the open ocean.
 Long wavelength, commonly 100’s of miles.
 Undetectable by ships in open ocean
 Open ocean velocity is 400 – 500 mph.
 About 4-5 hours from Alaska to San Diego (or Hawaii).
 Wave stacks up on continental shelf, ½ of the time
trough arrives first.
 Waves 30 – 100 ft are common
 Highest seismic seawave is thought to be 300 ft., 66
million years ago in the Gulf of Mexico
Energy and Mineral Resources
1) Mineral Resources
a) Mineral resources and igneous processes:
Metals such as gold, silver, copper, mercury, lead,
platinum and nickel can come from igneous processes
Hydrothermal solutions
 Formed from circulating warm, metal and mineral-rich
water heated by late stage magmas.
 Usually associated with sulfide minerals
 Commonly found: gold, silver, and mercury.
 Can be in concentrated veins or a disseminated
distribution.
Magmatic segregation:
 Separation of magma due to crystal settling and
deposition
 Layered intrusives
 Very rare
 Sedimentary features found in magma chamber
 Stillwater Complex in Montana has most of the free
worlds platinum.
Ex: Stillwater and Bushfeld complexes:
Diamonds
 Found in Kimberlite pipes
 Located in very tightly controlled areas.
 Monopoly by DeBeers a Dutch company.
 Graded by color, cut, size and clarity.
Pegmatites:
 Crystallize in a fluid-rich late stage of granitic magmas
 Large crystals of quartz, feldspar, muscovite,
hornblende and other exotics
b) Mineral resources and metamorphic processes
 Two types that rocks can undergo, contact
metamorphism and regional metamorphism
 The most common mineral deposits are formed by
contact metamorphism where hot fluids generate sulfide
deposits associated with metal ores such as zinc, lead,
copper, and iron. See above section in igneous rocks.
 Regional metamorphism can have larger areas of high
metamorphic facies. This can produce minerals form in
these higher metamorphic ranges such as garnets etc.
c) Placer deposits
 Deposition in a stream or river where heavy (high
specific gravity) material settles after being carried
downstream in the current of the river or stream.
 Placer minerals can be gold, tin, diamonds, and tungsten
minerals.
d) Nonmetallic mineral resources
Resources made from nonmetallic minerals include things
like:
 Building materials: sand and gravel aggregates, gypsum,
plaster, wallboard etc.
 Industrial minerals: garnets, diamonds, sulfur, salt etc.
b) Fossil fuels
 Formed from the organic remains of (mainly) plants
 Non-renewable energy source
 Provide the majority of the world’s total energy
demands
i) Coal
 Accounts for about 20% of nation’s energy needs
 Burning coal produces sulfur dioxide, an acidic gas that
contributes to the formation of acid rain
ii) Oil
 Easier to get out of ground and cheaper to transport than
coal
 Environmentally hazardous to transport
 USA is dependent on foreign sources of oil, we import
50% of the oil we use
iii) Natural gas
 Provides around 20% of the world’s consumption of
energy
 Very clean burning
 Burnt in power stations
 Used by many people to heat their homes
 Easy to transport along pipes
 USA has large reserves and is self-sufficient on natural
gas