Natural springs are important aquatic resources. They are a
reliable source of clean, high-quality groundwater that flows at a
relatively constant rate and temperature. Because springs are
dependable, they are an increasingly valuable supply of water for
people and wildlife, particularly during droughts. Fish,
salamanders, and invertebrates (animals without backbones, such as
insects and snails) thrive in clean, spring-fed streams. The moist
soil and lush vegetation along stream banks offer food and shelter
for birds and other animals.
The geology of groundwater: Groundwater is stored below
the surface of the earth within a structure called an aquifer. An
aquifer is made out of permeable or porous rock material and is
saturated (soaked) with groundwater. Aquifers can be defined as
confined and unconfined. Confined aquifers are rarer than
unconfined aquifers, and occur when the saturated zone lies between
two layers of impermeable rock. These types of aquifers result in
wells that do not require pumping, or artesian wells. Unconfined
aquifers are the most common and only have one layer of impermeable
material beneath the saturated zone. Below the permeable aquifer
layer, there is usually an impermeable layer that the aquifer rests
upon. This spring would be considered part of a confined
aquifer.
The very top portion of the aquifer is called the water table.
Water that is entering the groundwater system is called recharge
water. This occurs in what is known as a recharge area where the
watertable is below the surface of the land. The most obvious
recharge area for this spring is Lone Tree Bluff - the elevated
area you passed (or came over) to get here. Water reaches the
aquifer through a process known as infiltration or percolation. The
aquifer can also be considered a zone of saturation. The land above
the water table is in the unsaturated zone. Areas where groundwater
leaves the system are referred to as discharge areas. Springs form
where groundwater is forced up and onto the surface through
openings in the ground. This is caused by the differences in the
slope or "hydraulic gradient" in the aquifer. As rain falls and
percolates underground, it exerts pressure on the water already in
the aquifer, forcing some to the surface through natural
openings.
The pH of the groundwater is affected by the type of rock
material it moves through and how long it remains in contact before
it is released. In this area, the water in the aquifer would be
passing through limestone before emerging from the spring.
(To measure the pH, you will need to bring pH testing strips
which can be purchased through pool supply or science / educational
supplies stores.) Also, the temperature of shallow groundwater
is nearly uniform, reflecting the mean annual temperature of the
region.
To claim this earthcache you must complete the following:
1. Bring along your camera, a thermometer, and pH testing
strips.
2. Take a picture of yourself or your GPS at the spring and post
it with your online log.
3. E-mail me the answers to the following questions at the same
time you post your log:
• What is the temperature of the spring?
• What is the pH of the spring water?
The Geocache Notification Form has been submitted to Paul
Sandgren of the Wisconsin DNR. Geocaches placed on Wisconsin
Department of Natural Resource managed lands require permission by
means of a notification form. Please print out a paper copy of the
notification form, fill in all required information, then submit it
to the land manager. The DNR Notification form and land manager
information can be obtained at:
http://www.wi-geocaching.com/hiding
.
Sources:
http://academic.evergreen.edu/g/grossmaz/KIEPERME/
http://www.floridasprings.org/anatomy/jow/text/
http://www.ext.vt.edu/pubs/fisheries/420-537/420-537.html
http://www.kgs.ku.edu/Publications/pic11/pic11_1.htm