1. Chapter 11
Section 3 Water Underground
Bellringer
A family lives 50 km from the nearest stream or lake and gets water from a well. Where does the water in the well come from?

2. Chapter 11
Section 3 Water Underground
Objectives
Identify and describe the location of the water table.
Describe an aquifer.
Explain the difference between a spring and a well.
Explain how caves and sinkholes form as a result of erosion and deposition.

3. Vocabulary Chapter 11 groundwater water table aquifer porosity
Section 3 Water Underground
Vocabulary
groundwater
water table
aquifer
porosity
permeability
recharge zone
artesian spring
well
sinkhole

4. The Location of Groundwater
Chapter 11
Section 3 Water Underground
The Location of Groundwater
The water located within the rocks below the Earth’s surface is called groundwater.
The zone of aeration and the zone of saturation meet at a boundary known as the water table.
Rainwater passes through the upper zone, called the zone of aeration. Farther down, the water collects in an area called the zone of saturation.
The water table rises during wet seasons and falls during dry seasons.

5. Chapter 11
Section 3 Water Underground

6. Chapter 11
Section 3 Water Underground
Aquifers
A rock layer that stores groundwater and allows the flow of groundwater is called an aquifer.
The percentage of open space between individual rocks is called porosity.
A rock’s ability to let water pass through is called permeability.
A rock that stops the flow of water is impermeable.

7. Chapter 11 Section 3 Water Underground
Large particles, shown at left, have less total surface area—and so cause less friction—than small particles, shown at right, do.

8. Aquifers, continued Chapter 11
Section 3 Water Underground
Aquifers, continued
The best aquifers usually form in permeable materials, such as sandstone, limestone, or layers of sand and gravel.
The ground surface where water enters an aquifer is called the recharge zone.

9. Chapter 11
Section 3 Water Underground

10. Chapter 11
Section 3 Water Underground

11. Springs and Wells Chapter 11
Section 3 Water Underground
Springs and Wells
An artesian spring is a spring whose water flows from a crack in the cap rock of an aquifer.

12. Springs and Wells Chapter 11
Section 3 Water Underground
Springs and Wells
A human-made hole that is deeper than the level of the water table is called a well.

13. Chapter 11
Section 3 Water Underground

14. Underground Erosion and Deposition
Chapter 11
Section 3 Water Underground
Underground Erosion and Deposition
Groundwater can also cause erosion. However, groundwater causes erosion by dissolving rock.
Caves also show signs of deposition, such as stalactites, stalagmites, dripstone columns.

15. Underground Erosion and Deposition
Chapter 11
Section 3 Water Underground
Underground Erosion and Deposition
When the water table is lower than the level of a cave, the cave is no longer supported by the water underneath.
The roof of the cave can then collapse, which leaves a circular depression called a sinkhole.

16. Section Summary Chapter 11
Section 3 Water Underground
Section Summary
The water table is the boundary between the zone of aeration and the zone of saturation.
Porosity and permeability describe an aquifer’s ability to hold water and ability to allow water to flow through.
Springs are a natural way that water reaches the surface. Wells are made by humans.
Caves and sinkholes form from the erosion of limestone by groundwater.