recorded at depths of 4 to 12 meters (13 

 to 39 ft.) on June 30 and 40 to 44 meters 

 (131 to 144 ft.) on November 2. None was 

 observed in May or on October 22. The 

 thermocline temperatures were reduced from 

 7.5° to 20.3" (45.5° to 68,5° F.) to 5.8° 

 to 10.6° (42.4° to 51.1° F.). On the last 

 two dates the temperature had approached 

 uniformity between 10 and 12 degrees (50° 

 and 54° F.) from the surface to at least 

 35 meters (115 ft.). 



STATIONS OFF KENOSHA-RACINE 



Temperatures were obtained on 18 

 days off the Kenosha-Racine shore during 

 July 12-November 14, 1930, and May 8- 

 October 21, 1931, at 6 shallow stations 

 with depths of 55 to 70 meters (180 to 230 

 ft.) that averaged 62 meters (203 ft.) and 

 at 6 deep stations with depths of 83 to 

 113 meters (272 to 371 ft.) that averaged 

 102 meters (335 ft.) (table 6). 



The surface temperatures of both 

 years increased progressively in both 

 waters during the early periods of records 

 reaching on August 6 and 8 the mzixima that 

 ranged from 22° to 24° (72° to 75° F.). 

 By mid-November in 1930 the temperature 

 had been reduced to 7° (45° F.). The 1931 

 surface temperatures rose more slowly at 

 the deep than at the shallow stations even 

 though they had reached a higher climax 

 at the deep station on August 6. The few 

 comparable records suggest that the surface 

 waters were wariner in 1931 than in 1930 

 during the summer months. 



The temperatures of the upper sub- 

 surface waters followed the trends of the 

 surface temperatures except on September 2, 

 1931, when a uniform temperature of 19.8° 

 (67.6° F.) had extended from the surface 

 to a depth of 20 meters (66 ft.). In 1930 

 the temperatures had risen in August above 

 those of July down to depths of 20 and 14 

 meters (66 and 46 ft.) respectively in the 

 shallow and deep waters. In November, 

 the water had cooled in the upper 20 to 28 

 meters (66 to 92 ft.) to about 7° (45° F.) 

 but the ten^eratures of the greater depths 

 had actually increased. These changes 

 reduced the differences between the surface 

 and bottom temperatures to an average of 

 only 2.2° (4.0° F.). 



In 1931 the temperatures of both 



waters hzid increased progressively to 

 June 15 at nearly all depths, and there- 

 after to August 6 the increases were re- 

 stricted to the maximum depths that ranged 

 from 12 to 25 meters (39 to 82 ft.). The 

 temperatures had increased at the shallow 

 station on September 2 at all depths but 

 had decreased at the deep station down to 

 the 13-meter (43 ft. ) level on September 28, 

 remained about the same to a depth of 22 

 meters (72 ft.) on October 9, and declined 

 on October 21 to a depth of 22 meters (72 

 ft.). On these last two dates the tempera- 

 tures had risen respectively at depths 

 below 40 and 23 meters (131 and 75 ft.). 

 Temperatures below the shifted temperatures 

 of the upper waters remained constant, 

 reversed to the bottom, or fluctuated at 

 different depths. Uniform temperatures held 

 developed during both autumns at levels 

 above depths that ranged from 20 to 35 

 meters (66 to 115 ft.). 



Five-degree (41° F.) water appeared 

 late May 1931 near the surface. In both 

 years this temperature was restricted 

 during June-September to depths of 32 to 

 37 meters (105 to 121 ft.) at the shallow 

 stations cind 35 to 46 meters (115 to 151 

 ft.) at the deep stations. In late October 

 and early November it had descended to 50 

 to 56 meters (164 to 184 ft.) in deep water 

 but disappeared early November in shallow 

 water. 



The bottom temperatures, although 

 always higher in the shallow than in the 

 deep water at the same time of yeair, 

 increased very slowly during the summer 

 months and reached their maxima in the 

 fall. On May 8, 1931, the shallow-water 

 temperature was 3.8° (38.8° F.) at all 

 depths. On later dates in both years the 

 bottom temperatures of the shallow sta- 

 tions varied from 4.4° to 4,6° (39.9° to 

 40.3° F.) but rose to 5.1° to 6.0° (41.2° 

 to 42.8° F.) in November 1930. At the 

 deep stations they ranged from 3.9° to 4.2° 

 (39.0° to 39.6° F.) but increased in Octo- 

 ber and November to 4.5° to 4.6° (40.1° to 

 40.3° F.). The bottom waters of the deep 

 stations warmed more slowly than and 

 apparently rose not as high as those of 

 the shallow stations. 



In 1930 a thermocline was recorded 

 on July 12 in shallow water at depths of 

 8 to 14 meters (26 to 46 ft.) but none on 

 July 28 in deep water. On August 8, how- 



16 



