your knowledge of thermal
What does stratification look like in a lake? What evidence supports
thermal stratification? Why does
stratification occur? What factors might relate to thermal stratification?
You will need:
- Two clear cups or glasses
- One colored ice cube (add food coloring to the water before freezing)
- One gallon of cold (the colder the better) colored water (use
food coloring in the water)
be prepared to answer the following questions for class discussion:
- What do you think will happen when warm water is poured gently
into a glass with cold colored water? Carefully pour a 1/4 cup of
warm, clear water into the glass. (It is best if the warm water is
poured slowly in from the side of a tilted glass to avoid mixing.)
Try to ctreate a
glass of water that has two distinctly separate layers.
do you think will happen when a colored ice cube is placed in a glass
of warm water?Fill a glass with warm water. Place a colored ice cube
in the glass. Observe and record what happens for 5 minutes. Empty
the glass and fill it halfway with cold colored water.
did the colored water sink?
are convection currents?
you see convection currents in the glass? Explain.
do you think convection currents might/might not be found in lakes?
similarities and differences exist between the layered water and what
you might find in regional lakes during the summer?
might layering occur in lakes?
- You will be investigating temperature data from a WOW
lake to determine if there is evidence of thermal stratification.
Does your lake appear to act the same way as the glasses of water
in the demonstration?
will assign a lake and six dates to collect data for temperature profile
graphs. After data are collected and analyzed the class will examine
all of the temperature profile graphs in chronological order.
the WOW data for your lake, create temperature profile graphs. If
stratification is evident, label each of the layers
the folowing questions as you prepare for your final report:
the lake remain stratified throughout the summer?
variables might affect whether or not the lake remains stratified
throughout the summer?
might temperature profiles of other lakes in the region compare to
the lake monitored by RUSS?
is this type of information important to people who monitor and manage
or use our lakes?
temperature profile graphs and any written responses to questions in
to your teacher.