SCI EXAM 3 groundwater and karst topography
In Nebraska, the average saturated thickness of the Ogallala Aquifer is ____
342 feet
The Ogallala Aquifer underlies portions of _____ states in the central United States
8
Karst topography is most closely associated with limestone deposits that contain more than __________ calcium carbonate
80%
a large cave system is called a _____
a cavern
a place where water naturally seeps out of the ground is called _____
a spring
karst landscapes occur in regions that are now _____, but which were ____ at some point in the geologic past
arid now; humid then
a depression that forms when underlying rock dissolves, causing the surface to collapse is called a disappearing stream
false
a permeable layer of rock is called an aquiclude
false
another name for the ogallala aquifer is the north american aquifer
false
as water moves down the soil, it first move through the zone of saturation
false
karst landscapes typically contain nearly 50% calcium carbonate
false
the high planes aquifer is largely formed from thin, impermeable layers of rock
false
the zone of rock that is completely saturated with water is called the water zone
false
Once field capacity is reached, excess water flows downward as ______ water
gravitational
Karst landscapes are widespread in regions of _____ rainfall
high
Which letter in the diagram below corresponds to the well that will run dry in the dry season and produce water in the wet season?
shorter top of the well on the side (E)
a topographic depression that forms when underlying rock dissolves, causing the surface to collapse is called a ______
sinkhole
________ during this stage, a stream downcuts and the water table drops in response
stage 2
what feature forms in a cave when water, containing calcium carbonate, comes out of solution to create a formation on the ceiling?
stalactites
_______, these cave features form as a result of water evaporating, leaving calcium behind in a deposit that slowly grows up from the floor over time
stalagmites
__________ is the sinking of a surface as a result of the lass of support from underlying water, soils, or strata
subsidence
When water is pumped out of a well, which causes the water table around a well to drop, the initial feature formed is called _________
the cone of depression
the top of the saturated zone is called __________
the water table
_______, this type of karst topography occurs in humid subtropical areas where thick beds of limestone and high water tables exist
tower karst
a surface river or stream that flows into a sinkhole, moving into an underground river is called a disappearing stream
true
subsidence is the main reason venice, italy has continued to sink for nearly 1400 years
true
______, this is the threshold at which, for a given soil, water is no longer available for plant uptake
wilting point
Carlsbad Cavern is located in _________
North America (New Mexico)
the most heavily utilized aquifer in North America is the:
Ogallala Aquifer
