ii6 DISCOVERY REPORTS 



to 35-0 °/^,j, at the surface : an increase of only 0-4 "/^^^ in 500 m. This may be attributed 

 to upweUing, but the trend of isohaHnes between Sts. 70 and 71 should be interpreted 

 with caution, since conditions in the surface stratum may have altered considerably in 

 the three weeks which intervened between the working of these two stations (Fleming, 

 1930). Likewise the surface change from 35 °j^^ inshore to 36-0 °/^^ in the west takes 

 place gradually. From this section it is impossible to say where the influence of upwelled 

 water is no longer felt and so to ascribe positive limits to the Peru Coastal Current. 



STATIONS 8,0 



Fig. I . Salinity section of the eastern South Pacific based on ' Carnegie ' Sts. 70-80. The section runs 



westwards of Callao. (After Sverdrup.) 



The other lines run by the ' Carnegie ' and figured by Sverdrup furnish no better 

 evidence on this point, but suggest that the influence of coastal upweUing is felt less 

 and less as distance from the coast increases, that it has no abrupt end, and is felt at 

 greater distances from the shore in low latitudes (off Peru) than in high latitudes (off 

 Chile). Thus in lat. 25° S, the data figured by Sverdrup in figs. 6 and 8 give grounds 

 for supposing that the influence of upweUing might be felt as far as 600-700 miles 

 offshore: the isotherm of 15° C. for example, being found nowhere as deep within this 

 distance as it is at some 680 miles from the coast. In 15° S the influence of upwelled 

 water may be felt at 1 200-1 500 miles, and at 5° S, where water is travelling westwards, 

 its influence may be carried indefinitely. 



