Journal #10
1. Where is our source of fresh water?
2. What is groundwater?
3. How do we access (or get) groundwater?
Water Beneath the Surface
 Surface water that does not run off into streams
and rivers may seep down through the soil.
 There, the water fills spaces, or pores, between
rock particles in the upper part of the Earth’s crust.
 Water that fills these spaces is called groundwater.
 Groundwater is an important source of fresh water
in the U.S.
Aquifers
 A body of rock or sediment in which large amounts
of water can flow and be stored is called an aquifer.
 For water to flow freely through an aquifer, the
pores in the aquifer must be connected.
 The ability for the water to flow freely is affected
by porosity and permeability.
Porosity
 The percentage of the total volume of a rock or
sediment that consists of open spaces is called
porosity.
 Example: a sponge
 On factor that affects porosity is sorting.
 Sorting is the amount of uniformity in the size of
the rock or sediment particles.
Poorly Sorted Sediment
Well Sorted Sediment
Sorting
 Most particles in a well-sorted sediment are about
the same size, and few smaller particles fill the
spaces between them.
 Poorly sorted sediment contains particles of many
sizes.
 Small particles fill the spaces between large
particles, which makes the rock less porous.
 Rock that has tightly packed particles contains few
open spaces and has low porosity.
Permeability
 The ease with which water passes through a porous
material is called permeability.
 For a rock to be permeable the open spaces must
be connected.
 Permeability is affected by size and sorting of the
particles
 Larger and well sorted particles are more
permeable.
 Example: Clay is flat and finely grained. Do you
think it is permeable to water?
Review:
1. What is groundwater?
2. Where is groundwater stored?
3. What two things affect the rate at which
water flows through an aquifer?
Review
Review
1. The ease with which water passes through
a porous material is called
__________________.
2. Can a rock be permeable if the pores are
not connected?
Your Assignment
 Correct your quizzes from last week.
 Vocabulary Squares
1. Ground water
2. Aquifer
3. Porosity
4. Poorly sorted sediment
5. Well sorted sediment
6. Permeability