Conductivity and Stratification in Lakes

Group Names: _________________________________________________

Date: _______________________

Knowledge Base

1. What general factors influence conductivity in lakes?

Data Collection

2. 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.

Data Management and Analysis

3. Are there any dates where data are missing? What factors may cause a lack of data when research is being conducted?
   
   
   
   
4. 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?
   
   
   
   
5. 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

6. Would you get a more representative profile if you eliminated some of the data points from your average? Why?
   
   
   
   
7. What does the Ice Lake profile tell you about how conductivity varies with depth?
   
   
   
   
8. Why does conductivity change with increasing depth?
   
   
   
   
9. 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

10. 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.