groundwater
Groundwater any water found underground.
-occupies pores between grains
and fractures and solution openings in rock.
recharge area
Water enters the groundwater flow system in
recharge areas
discharge area
groundwater flow system
in discharge areas
saturated zone
the subsurface zone in
which all rock openings are
filled with water
vadose zone
Above the water table is a
generally unsaturated
region
water table
� the top of the saturated
zone
� Water level at surface of
most lakes and rivers
corresponds to the water
table
spring
- a place where water
flows naturally from the rock
or sediment onto the ground
aquifer
a geologic unit that yields economically
significant quantities of water
aquitard
a geologic unit that does not hold quantities of water
permeability
the capacity of a rock to transmit fluid
through pores and fractures
- Granites, schists, unfractured limestones are relatively
impermeable
porosity
the percentage of rock or sediment that
consists of voids or openings
98% of the world's available fresh water
is groundwater
good aquifer
Good aquifers include:
- Sandstone
- Conglomerate
- Well-jointed limestone
- Sand and gravel
- Fractured volcanic rock
a good aquitard
� Good aquitards include:
- Shale
- Clay
- Unfractured crystalline rocks
confined and unconfined aquifer difference
Confined
Has a water table, and is only partly filled with water
Unconfined
Completely filled with water under pressure
Why does groundwater flow?
Gravity (gravitational potential energy)
- causes water to flow down slope
Hydraulic head (elevation + pressure)
Can groundwater flow uphill?
Yes!
How fast does groundwater flow?
Relatively slowly - centimeters to meters per day
Groundwater Challenges
1. Groundwater depletion/availability
2. Groundwater-caused land sinkholes
3. Groundwater contamination
Know what the primary agent of erosion is.
Running water is the
primary agent of
erosion
headwaters
- Headwaters - upper part of stream near its source in the mountains
mouth
- Mouth - place where a stream enters sea, lake or larger stream
deposited by the stream
channel
- Channel - a long, narrow depression eroded by a stream into rock or sediment
stream bank
� Stream banks - sides of channel
- Floodplain - flat valley floor composed of sediment
stream bed
� Streambed - bottom of the channel
floodplain
- Floodplain - flat valley floor composed of sediment deposited by the stream
drainage basin
Drainage basin - the total area drained by a stream and its tributaries
watershed
Watershed: all the land that drains to a stream
tributary,
- Tributary - a small stream flowing into a larger one
- Can be outlined on a map by drawing a line around the region drained by all of
the tributaries of a stream
divide (continental divide)
- Divide - ridge or strip of high ground that divides one drainage basin from another
� Continental divide separates the streams that flow into the Pacific from those
that flow into the Atlantic and Gulf of Mexico
bars
Bars - ridges of sediment (usually sand or gravel) deposited in the
middle or along the sides of a stream
floodplain deposits
Floodplain deposits - broad strips of land built up by sedimentation on either side of a stream channel
- sediments are left behind as flood
waters slow and recede at the end of flood events
natural levee
Natural levees - Main channel has slightly raised banks with respect to the floodplain
deltas
Deltas - a body of sediment deposited at the mouth of a river when the flow
velocity decreases
alluvial
Alluvial fans - large, fan- or cone-shaped piles of sediment that usually form (desert regions)
meander stream
Meandering Stream - typical of moist climates
Erosion of cutbank; deposition of point bar
braided streams.
typical of desert climates
(flash flow events)
- Dendritic
- drainage pattern
resembling the branches of a tree
most common
- Radial pattern
- streams diverge
outward like the spokes of a wheel
- Rectangular pattern
- tributaries
have frequent 90� bends and join
other streams at right angles
- Trellis pattern
- parallel streams with
short tributaries meeting at right
angles
downcutting
- Process of deepening a valley by erosion of the streambed
- V-shaped valleys from of river channel
lateral erosion
- widens stream valleys
headward erosion
- slow uphill growth of a valley
stream discharge
Volume of water passing a point in the
stream per unit time (Q)
hydrograph
A Plot of Flow Rate over Time
baseflow
ground water given to streams
runoff.
stream gets its water from runoff and groundwater
floods
Flood - when water levels rise and overtop the banks of a river
flood recurrence intervals.
The percent probability a flood of a certain size will occur each year
beach
a strip of sediment (usually sand or gravel) from the
low-water line inland to a cliff or zone of permanent
vegetation
wave is
ocean waves (not tsunamis) are created
by wind blowing over the surface of the water
waves are formed
Movement of water circular path (orbit)
� In deep water, energy advances with the wave, but the water does not
� Orbital motion in waves decreases with depth until it is essentially gone
Longshore drift
Waves hit the coastline at a slight angle, pushing water and sediments
� Longshore drift is the movement of sediment parallel to shore
spits
Spits - build out into the open water off a point of land
longshore drifts
baymouth bars
Baymouth Bars - ridges of sediments that cut bays off
from the ocean
longshore drifts
fjord
drowned glacially cut valleys
jetties
Jetties (along inlets)
groins
� Groins (on beaches, perpendicular to shoreline)
seawalls
Sea Walls (on beach, parallel to shoreline)
breakwaters
� Breakwaters (beyond beach, parallel to shoreline)
beach nourishment
Beach Nourishment (adding sand to beach)
Emergent Coastlines
sea level lowers with respect to
the land (the land emerges)
Submergent Coastlines
Sea level rises with respect to land (the land submerges)
Glacier
- a thick mass of ice that originates ON LAND
from the accumulation, compaction, and
recrystallization of snow
zone of accumulation
If input > output, the glacier grows
precipitation
zone of ablation
If input < output, the glacier shrinks
melting
evaporation
calving
snowline
Snow line = Equilibrium line
plucking
Plucking
- lifting of rocks
abrasion
- Glacial polish: rocks within the ice acting like sandpaper to
smooth and polish the surface below
u-shaped valley
valleys eroded out by glaciers into the shape of a U
hanging valley
small abandoned glacial valley suspended on a mountain above the main glacial valley
pater noster lakes
A chain of small lakes in a glacial through that occupies basins created by glacial erosion.
cirques
A large bowl-shaped valley carved out of a mountain side by a glacier.
tarns
mountain lake or pool, formed in a cirque excavated by a glacier
ar�tes
are jagged ridges that form between two or more cirques cutting into the same mountain
horns
peaks shaped by glaciers that have carved a mountaintop on two or more sides
moraines
the piles of rocks, sand and soil that form ridges made by glaciers
till
the mixture of sediments that a glacier deposits directly on the surface
outwash
...
erratic
irregular, wandering, having no fixed course; large rock deposited by a glacier
Drumlin
a long mound of till that is smoothed in the direction of the glacier's flow
esker
long ridge of material deposited by a meltwater stream flowing beneath a glacier
kettle
(geology) a hollow (typically filled by a lake) that results from the melting of a mass of ice trapped in glacial deposits
During which epoch of time did the most recent "ice ages" occur?
The most recent series of
"ice ages" occurred during the
Pleistocene Epoch
Know why Milankovich cycles are related to glacial/interglacial cycles (NOT the specifics).
Milankovich Astronomical Cycles: irregularities in the motions of the Earth that result in changing distribution of solar insulation around different parts of the Earth.
Know how high the IPCC estimates global sea level rise will be by 2100.
3.5 to 34.6
inches by 2100
desert
an arid (dry) region with less than 25 cm
precipitation/year
eolian
landscape influenced by wind
arroyo
Streambeds flow intermittently, typically
during/after heavy rains
predominant agent of erosion in deserts
Water
Desert Pavement
- rocks left behind after wind carries fines away
Blowouts
- depressions carved by wind
Yardangs
- remnants of soil left behind by wind
Ventifacts
- sandblasted rocks
Sand Dunes
- mounds of loose sand piled up by the wind
Loess
- wind-blown silt