8 



Indiana University Studies 



Table I. Showing the Area, Maximum Depth, Average Depth, and 

 Volume of the Lakes whose Maps Appear in This Report. 







Maximum 



Average 



Volume 



Lake 



Area 



depth 



depth 



eu.M. 



Manitou 



3,265,607 



14.8 



2.997 



9,787,024 



Yellow Creek 



576 , 785 



22. 



10. 



5,767,850 



Hammon (Big Barbee) 



1 , 062 , 294 



15. 



6.7319 



7,150,260 



Blew 



418,635 



18.6 



7.327 



3,047,320 





Q7Q qoQ 



O < O , iJKjiJ 



in 4 



All 70 





Beaver Dam 



794,979 



20. 



4.2958 



3,415,071 



Sawmill 



85,084 



10. 



3.3463 



284,716 



Ridinger 



526,848 



13.3 



6.44 



3,392,901 



Kuhn 



268,709 



8.2 



3.912 



1,051,193 



Dan Kuhn 



543,117 



7.9 



2.588 



1,405,586 





621,998 



11. 



3.326 



2,068,765 



summer. The temperatures in the appended tables are all 

 summer records. From what is known of other lakes it is often 

 possible to infer antecedent events from summer temperatures. 



It may be well to review, briefly, the series of events that occur 

 in a lake from the melting of the ice to the establishment of 

 summer conditions. 



When the ice first melts in the spring, the surface of the water 

 is at 0°C. The water at the bottom of the lake is slightly warmer 

 than that, but less than 4°C. Hence the lower layers are shghtly 

 heavier. This slight difference in density is further reduced 

 by the absorption of heat at the surface, so there is very little 

 resistance to mixture. As a result, the first windy day after the 

 ice has disappeared is hkely to mix the water of the lake com- 

 pletely, i.e. to cause the spring ^'turnover". 



As the temperature is generally increasing at this season, 

 the surface of the lake is absorbing heat almost constantly. 

 If the weather is windy, this surface water is mixed with that 

 below so that the lake again becomes homothermous. 



The thermal resistance to mixture of two adjacent strata of 

 water increases directly as their difference in temperature and as 

 their thermal difference from 4°C. When there occurs a warm 

 period of little wind the heat is absorbed and remains in the 

 upper meter or two of water. The thermal resistance to mixture 

 between this layer and the one immediately beneath it is the 



