Chapter 10 (exam three)
43 Cards in this Set
Front | Back |
---|---|
runoff
|
water that flows along the surface and does not seep in to the ground
|
Zone of aeration
|
Undersaturated zone above the water table
includes belt of soil moisture
Water here cannot be pumped by wells
|
belt of soil moisture
|
water that holds on to soil particles in the near-surface zone
|
water table
|
the upper limit of the zone of saturation
the contact between the one of aeration and the zone of saturation
|
Zone of Saturation
|
Water not held as soil moisture percolates downward
Water reaches a zone where all of the open spaces in sediment and rock are completely filled with water
|
groundwater
|
water within pores
|
variations in water table
|
rainfall
depth
mimic above topography
permeability
|
permeability
|
the ability of a substance to transmit fluid
|
Gaining streams
|
streams gain water from the inflow of groundwater through the streambed
can be both gaining and losing
|
Losing streams
|
streams lose water to the groundwater system by outflow through the stream-bed
Loosing streams may be disconnected from the GWT
|
aquifer
|
permeable rock strata or sediment that transmits groundwater freely
Rock types that commonly act as aquifers include medium to coarse grained sandstones and gravels
|
aquitard
|
an impermeable layer that hinders or prevents water movement
Shale and crystalline (igneous and metamorphic) rocks are good aquitards because water can not easily flow through them
|
Ogalla aquifer
|
shed off Rocky Mountains (SD to Tex)
contains 950 trillion gallons of water
main source of water for ag in high plains
|
springs
|
Occur where the water table intersects Earth’s surface
Natural outflow of groundwater
Can be caused by an aquitard creating a localized zone of saturation which is called a perched water table (separate from main groundwater table)
|
cave formation
|
usually limestone
Groundwater that dissolves soluble rock below the surface will form caverns, also known as caves
both living and dead caves
living have balance between solution and dissolution
dead stop interacting with groundwater
|
dripstone (tavertine)
|
Calcite deposited as dripping water evaporates
Collectively, they are called speleothems
|
flowstone
|
massive deposits of travertine
|
Stalactites
|
hang from the ceiling
|
Stalagmites
|
form on the ground
|
soda straws
|
hollow tubes
earliest growth of stalactites
|
columns
|
form when stalagmites and stalactites meet
|
curtains (or bacon)
|
thin sheets of travertine that hang from the ceiling or wall
|
shelfstone
|
limestone precipitates on the top of a pool of water creating a shelf, with a column underneath
|
boxwork
|
looks like boxes on ceiling
|
popcorn
|
looks like popcorn on rock formations
|
crystal formations
|
calcite
aragonite
gypsum
|
Karst topography
|
Dissolved limestone that is very close to the surface results in landscape features
|
sinkholes
|
When caverns form close to the surface, the roof may become unstable and collapse under its own weight creating a sinkhole
major sources of water quality issues
cause damage to homes and property
|
disappearing streams
|
streams running along the surface may be swallowed up into a sinkhole or a cave
|
natural bridges
|
remnants of a cave passage
formed when sinkholes collapse on two sides
not only way they can form
|
karst towers
|
last remnants of massive limestone layers that form enormous “towers”
common in tropical regions where limestone is eroded quickly by rainfall
|
hot springs
|
water is heated by cooling of igneous rock below
|
geysers
|
Groundwater heats, expands, changes to steam, and errupts
water erupts with great force within hot spring
|
Thermophiles
|
organisms that can survive (and thrive) in extreme heat environments
|
Darcy's Law
|
Q is discharge (volume of water flowing through area)
K is hydroloic conductivity (quickly or slowly fluid flows through specific substance)
A is cross sectional area
h1 and h2 are hydrolic gradient ( water table slope)
|
porosity
|
the percentage of void, or pore space in a rock body
|
Intergranular porosity
|
due to spaces between grains
Sandstones, claystones, conglomerates
|
bedding plane porosity
|
due to space between the bedding of rock layers
Sedimentary rocks
|
fracture porosity
|
due to spaces along joint sets and fractures withing a rock
All rock types
|
Solution (vuggy) porosity
|
due to cavities within the rock that have dissolved from mild acids
Soluble rocks: Limestones, marble, rock salt, gypsum
|
drawdown
|
lowering of the water table
from wells
|
cone of depression
|
from wells
cone in top of groundwater table where the well is
|
groundwater pollution
|
sewage is most common problem
fertilizers and pesticides
industrial materials and chemicals
landfills
mine tailings
|