STATIONS OFF 

 MANITOWOC-TWO RIVERS-KEWAUNEE 



Temperatures off the Manitowoc -Kewau- 

 nee shore were obtained in 1930 on four 

 dates from June 25 to August 12 and in 1931 

 on seven dates during June 25-October 15 

 (table 8). Depths of the 5 designated shal- 

 low stations varied from 43 to 54 meters 

 (141 to 177 ft.) in 1930 and from 60 to 87 

 meters (197 to 285 ft.) in 1931 and of the 

 4 deep stations rsmged from 140 to 145 

 meters (459 to 476 ft.) in 1930 and from 

 145 to 172 (476 to 564 ft.) in 1931. 

 The averages of these four series were 46, 

 79, 143, and 157 meters (151, 259, 469, and 

 515 ft.). 



The 1930 surface temperatures of the 

 shallow stations rose from 10,6° (51.1° F.) 

 on June 24 to 16,7° (62.1° F.) on July 21 

 and then remained virtually constant on the 

 two dates thereafter. At the deep stations 

 they rose at first more slowly than at the 

 shallow stations but increased progressively 

 from 9.9° (49,8° F.) to 18.6° (65.5° F.), 

 surpassing the shallow-water temperatures 

 about two degrees on the last two dates. 



In 1931 the surface temperatures of 

 the shallow stations increased progressively 

 from 13.5° (56.3° F.) on June 25 to a maxi- 

 mum of 19.6° (67.3° F.) on August 3 and de- 

 creased to 14,5° (58.1° F.) on September 10, 

 the last date. The depths of these stations 

 were almost all about 1 3/4 greater than 

 those of the designated shallow stations of 

 1930, Only on four dates from August 12 to 

 October 15 were temperatures obtained at 

 deep-water stations in 1931, Their surface 

 temperatures declined progressively from 

 19.4° to 12.1° (66.9° to 53.8° F.). On 

 corresponding dates the surface temperatures 

 of the deep water exceeded those of the 

 shallow water. These temperatures were 

 higher in 1931 than in 1930 on the proximate 

 dates. 



The 1930 subsurface temperatures 

 did not always follow the trend of the sur- 

 face temperatures at the shallow stations, 

 but those of the deep water did, having 

 increased on each succeeding date down to 

 at least 30 meters (98 ft,). The shallow- 

 water temperatures of the upper 20 meters 

 (66 ft.) did increase by July 21, but on 

 July 30 upwelled water had reduced the tem- 

 peratures up to at least the 11-meter (36 

 ft.) level (this had not occurred at the deep 



station). On August 12 they had increased 

 considerably at all depths rising to around 

 16.5° (61.7° F.) throughout the upper 15 

 meters (49 ft.) and to an unusually high 

 degree of 6.1° (43,0° F.) at the bottom. 

 At the deep stations the subsurface temper- 

 atures gradually rose above those of the 

 shallow stations at corresponding depths 

 except at certain levels below 11 meters 

 (36 ft.) on August 12 when warm water had 

 reached a depth of at least 12 meters (69 

 ft.) at the shallow station. 



In 1931 the subsurface temperatures 

 of various upper levels tended to follow 

 to a certain extent the seasonal trend of 

 the surface temperatures of both shallow 

 and deep water. Those of the shallow sta- 

 tions had increased by July 8 down to a 

 level of 35 meters (115 ft.) but only to 

 cibout 11 to 13 meters (36 to 43 ft.) on 

 August 3 when apparently upwelled water 

 had lowered the temperatures at different 

 levels between 11 and 30 meters (36 and 98 

 ft.). By August 12 the temperatures had 

 risen at all depths but noticeably down to 

 a depth of 50 meters (164 ft.); those of 

 the upper 25 meters (82 ft.) maintained a 

 uniformity close to 19° (66° F.). On Sep- 

 tember 10 the temperatures had declined at 

 all depths, perhaps the result of upwelling. 



In the deep water the subsurface 

 temperatures of the upper levels decreased 

 progressively late in the year down to 

 depths that ranged from 11 to about 45 

 meters (36 to 148 ft.) but those of the 

 lower levels increased in October either 

 to the bottom or to some depth between 60 

 and 90 meters (197 and 295 ft.). A nearly 

 uniform temperature extended down to 20 to 

 22 meters (66 to 72 ft.) on all dates ex- 

 cept September 10. Even though the two 

 stations occupied on August 12 and Septem- 

 ber 10 were only about 7 miles apart, their 

 temperatures differed markedly. In August 

 they were the same down to the 17 meter 

 (56 ft.) level; then the deep-water temper- 

 atures declined much more rapidly. In 

 September the temperatures were considerably 

 higher in the deep than in the shallow 

 water at corresjxsnding depths, especially 

 in the upper 25 meters (82 ft.). 



During the period from late June to 

 early fall a temperature of 5° (41° F.) 

 was usually confined to depths of 27 to 37 

 meters (89 to 121 ft.) at the shallow sta- 

 tions, except when cold water had welled 



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