804 EIGHTH PACIFIC SCIENCE CONGRESS 



the outer limits of the Gulf of Guayaquil are completely under the 

 influence of the very far northward reaching outlet of the Peruvian 

 Current, whilst only the inner parts of the Gulf indicate higher tem- 

 peratures belonging to waters which may be able at any moment to 

 form the "real Nino Current" (Schweigger, 1945). 



The maps for April (Figs. 8-11) contrast strongly with those for 

 March. It is evident, in all of them, the depression of the sea-surface- 

 temperatures as compared with March. Only in 1953 (Fig. 11) the 26° 

 isotherm was observed nearer to shore than in March of the same year. 

 The diminution of the surface temperatures is especially visible in the 

 southernmost part of the Peruvian littoral and also in the Gulf of Gua- 

 yaquil where all temperatures are reduced. Unfortunately, data are 

 missing for April 1941 north of 9°S and south of 14°30'S, and it is 

 just this year which seems to have shown the greatest anomaly of all 

 the years since 1925. The extended voyage of the author to the region 

 W of Pisco (12°-]4°S) allowed him to trace the isotherms over a great 

 area in the open sea, and it must be deduced from the distribution of 

 the hourly observed surface-temperatures that in April 1941 the iso- 

 therms for 26°, 25° and 24 °C had a course nearly perpendicular to 

 the continental coast, at least from a certain distance on, being space 

 left for lower temperatures along the Peruvian shore. 



Three parts of the coast deserve our greatest interest: The Gulf 

 of Guayaquil, the area included by the latitudes 9° and 10° S and the 

 region between Atico-Ilo-Arica. The position of the isotherms in the 

 Gulf of Guayaquil for March and April 1953 (Figs. 7 & 1 1) leaves no 

 room to doubt that the high sea temperatures are derived from the 

 NW, which can only mean an advance of the Equatorial Countercur- 

 rent, corroborated also by low salinities. In March 1939, as in March 

 and April 1947 (Figs. 4, 6 and 10), the highest temperatures in this 

 zone belong without doubt to the interior parts of the Gulf and extend 

 from there to the W and SW. The conditions in April 1939 and in 

 March 1941 (Figs. 8 and 9) cannot be determined satisfactorily in view 

 that observations are available only for one route of navigation, al- 

 though in March 1941 the highest sea temperature (27.5° C) was observed 

 E of 81 °W whilst in the half-degree-square just W of that meridian 

 the surface temperature was found half a degree lower (27.0°C). The 

 warm waters south of Cabo Blanco, and especially those southwest of 

 Aguja Point, must be brought in connection with the open ocean, but 

 not with certainty with the Equatorial Countercurrent, although in 

 March 1941 very low salinity was observed between 8° and 6°30'S 

 which induced one to believe that these waters had come from the 

 Equatorial Countercurrent. But as these titrations of salinity had to 



