Transcript water - Cloudfront.net

January 13, 2014
Agenda
1. Roll
2. Student Survey
3. PowerPoint titled: Water
Underground
4. Possible Video “Wonder Beneath”
Subject Area: Water Underground
EQ: How are the surface features of the
earth changed with weathering and
erosion of water?
Questions:
1. Where is the location of a water table?
2. What are the characteristics of an
aquifer?
3. How do caves and karst topography
form as a result of erosion and
deposition?
Water Underground
We can see surface water in streams, lakes,
and rivers. There is also water flowing
underground. The water located within the
rocks below the Earth’s surface is called
ground water. Ground water plays an
important roll in erosion and deposition.
Location of Ground Water
Surface water seeps into the soil and
rock. This underground area is
divided into two areas. The first zone
is the zone of aeration. It is located in
the upper regions and is only filled
completely with water after a rain.
Zone of Saturation
The second zone is the zone of saturation.
This is farther down and the spaces
between the rock particles are filled with
water.
Water Table
The zone of aeration and the zone of
saturation meet at an underground
boundary called the water table. It rises
during wet seasons and drops during dry
seasons. In wet regions it can be right
below the surface and in desert regions it
could be hundreds of meters underground.
Partner Question:
What is the Water Table?
The Water Table is …
Aquifers
A rock layer that stores and allows the flow
of ground water is called an aquifer.
Partner Question:
What is an Aquifer?
An Aquifer is …
Porosity
A rock layer must have two characteristics in
order to qualify as an aquifer. First the rock
layer must be porous. A rocks porosity is
the amount of open space between
individual rock particles.
Permeability
Second the rock layer must allow water to
pass freely through it, from one pore to
another. A rocks ability to let water pass
through it is called permeability.
The Best Aquifers
The best aquifers
are formed of
sandstone,
limestone, or
layers of sand
and gravel. They
are located all
over the United
States. Is there
one near where
we live?
Springs and Wells
If the water table reaches the Earth’s
surface, water will flow from the ground,
forming a spring. Lakes form in low areas,
where the water table is higher than the
Earth’s surface.
Artesian Spring
Artesian springs are springs that form where
cracks occur naturally in the cap rock and
the pressurized water in the aquifer flows
through the crack to the surface.
Wells
A well is a human-made hole that is deeper
than the level of the water table, the wells
will fill with ground water.
Underground Erosion and
Deposition
Most ground water will move slowly and still
cause erosion and deposition. Ground
water will erode certain types of rock by
dissolving the rock.
Caves
Most of the worlds caves formed over
thousands of years as ground water
dissolved limestone. Inside a cave there
can be formed stalactites and stalagmites.
These are formed by dissolved limestone
and water dripping from the ceiling to the
floor.
>>>
Karst Topography
Areas where the
effects of groundwater erosion are
noticeable at the
surface are said to
have karst
topography. The
roof of a cave can
collapse causing a
sinkhole on the
surface.
Partner Question:
What are some of the
features formed by
underground erosion
and deposition?
Some features are …
Summary
1. Answer the essential question “How is the
surface features of the earth changed with
weathering and erosion of water? ”
2. Your answer needs to be in complete sentences.
3. Place your answer at the bottom of the notes we
did today.
4. Make sure you include how caves are made.
5. Use your notes to get the answers.
Video Questions for
“The Wonder Beneath”
1. What did you know?
_____________________________________________
_____________________________________________
_____________________________________________
2. What did you learn?
_____________________________________________
_____________________________________________
_____________________________________________
3. What do you want to know?
_____________________________________________
_____________________________________________
_____________________________________________
Review
1. What is the relationship between the
zone of aeration, the zone of saturation,
and the water table?
Homework
Chapter 10, Section 3 in the purple
workbook. This is found on pages 77-78.
Link to PowerPoint