Conductivity
and Stratification in Lakes
Group
Names: _________________________________________________
Date:
_______________________
Knowledge
Base
- What
general factors influence conductivity in lakes?
Data
Collection
- Form
a team of 3-4 members. Go online and download conductivity data for
Ice Lake from June 15, June 30, July 15, July 30, August 15, and August
30 for 1998 and the same dates for 2000. Use the table below to record
your data. In the last column, average the conductivity values for
each
depth.
Depth
in
meters
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6/15
1998
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6/30
1998
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7/15
1998
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7/30
1998
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8/15
1998
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8/30
1998
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6/15
2000
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6/30
2000
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7/15
2000
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7/30
2000
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8/15
2000
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8/30
2000
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Ave.
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2
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3
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4
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5
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6
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7
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8
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9
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10
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11
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12
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13
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14
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Data
Management and Analysis
- Are there any dates where data are missing? What factors may cause a
lack of data when research is being conducted?
- Create a graph of your data for each year, plotting conductivity
vs. depth. Draw a separate line for each date. Remember to label the
axes and identify each line. Do the lines illustrate a trend of changes
in conductivity with depth? What kind of trend?
- Plot the average conductivity values on both graphs with another
line. Does the average conductivity graph parallel the trend illustrated
when the data from individual dates were plotted?
Interpretation
of Results
- Would you get a more representative profile if you eliminated
some of the data points from your average? Why?
- What
does the Ice Lake profile tell you about how conductivity varies with
depth?
- Why does conductivity change with increasing depth?
- If you plotted conductivity against depth for other WOW lakes for
the same time period, would you expect the profile to be similar?
Why or why not?
Reporting
Results
- Describe a "typical" conductivity profile during midsummer
in Ice Lake.
Hand in
the worksheet, the data table, and the 1998 and 2000 graphs for conductivity
in Ice Lake. Be sure all team members names are on each item.
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