January 13, 2014Agenda
1. Roll2. Student Survey3. PowerPoint titled: Water
Underground4. Possible Video “Wonder Beneath”
Subject Area: Water UndergroundEQ: 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 WaterSurface 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 TableThe 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 …
PorosityA 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 AquifersThe 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.
CavesMost 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.
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Karst Topography
Areas where the effects of ground-water 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