TEMPERATURE OF THE LAGOONS. 149 



TEMPERATURE OF THE LAGOONS. 



The bottom temperature of the lagoons of the Maldives differs but little 

 from that of the surface. 



At Addu, the northern part of Suvadiva, Haddummati, Kolumadulu, 

 Fadiffolu, and Tiladummati, the temperatures were identical. The bottom 

 temperature was slightly colder (from 0°.5 to 1° ) at North Malosmadulu, 

 the southern part of Suvadiva, Mulaku, and Ari. While at Felidu and North 

 Male the bottom temperature was 0°.5 warmer than the surface. The 

 water was from 0°.5 to 6° warmer than the air at Haddummati, Suvadiva, 

 Addu, Kolumadulu, Felidu, Fadiffolu, North and South Malosmadulu, North 

 Male, and Tiladummati. In the southern part of Ari we found the tem- 

 perature of the air 1° greater than that of the surface. 



The water of the atolls is evidently heated to a temperature above that 

 of the adjoining oceanic waters. According to the observations of the 

 " Valdivia " between the Maldives (Suvadiva) and the Chagos Archipelago, 

 the temperature at a depth of fifty metres was 26° Centigrade, and that 

 at seventy-five metres had dropped to 21°.8 Centigrade. 1 



The following observations were made : 



Temperatures usually taken at 8 p.m. 

 Dec. 28, 1901. Air, 84 at anchor off Ariadu (Ari). 

 Surface of water, 83\5 (Fahrenheit). 

 Bottom, 82°, thirty fathoms. 

 Dec. 29, 1901. South part of Mulaku at anchor in thirty-four fathoms. 

 Surface, 83°. 

 Bottom, 82°. 



1 Temperatur Curven, PI. XXIII., Wiss. Ergebnisse d. Deutschen Tiefsee Expedition. Text, 

 Erster Band, 1902. 



