Vol. 4] 



Eohvay.—Cold Water Belt. 



perature is here shown. The great torrid belt with an annual 

 range of 10° or less shows a northward pointing extension off 

 Lower California similar to that on the map of maximum temper- 

 atures and to be accounted for in the same way. An interesting 

 minor point, bearing on the accuracy of the map, is shown by 

 the small area around the southern part of Lower California, 

 which is charted as having an annual range of 20°. This in- 

 cludes the locality where Buchanan reports cold water due to 

 upwelling. It will be seen by reference to the Pilot Charts that 

 while the main current from the southeast is constant during 

 the year, the inshore current varies with the seasons, sometimes 

 being from the north and sometimes from the south. This varia- 

 tion indicates of course a great annual range of temperature. 

 This mutual confirmation of the two maps in this small area is 

 worth noting as a correlation to the warning given by the authors 

 as to the insufficient data upon which their work rests. 



Another variation in PL 35 B is the southward extension of 

 the belts of an annual range of from 10° to 15°. This occurs at 

 about 120° West Longitude and extends to Latitude 10°. This 

 is probably accounted for by a variation in the strength of the 

 south flowing California current and of the northwest flowing 

 current off Mexico. This variation is somewhat indefinitely 

 shown on the Pilot Charts by a change in the extension of these 

 currents during the spring and the autumn seasons. 



Temperature of Ocean Bottom. — PI. 36 is a reproduction of 

 the Deutsche Seewarte chart showing ocean depths in the North 

 Pacific. The principal areas which according to Murray have a 

 bottom temperature of under 35° are indicated by oblique pa- 

 rallel lines. 



The contours on this chart are in meters ; the first line indi- 

 cating 200 m. and the others the successive even thousands In 

 the region to the eastward of Kamchatka these contours must 

 be modified to agree with recent soundings of the Albatross. A 

 sounding of 5,700 M. (3,117 Fm.) was obtained in Lat, 54°-51', 

 Long. 163°-46' E and other soundings indicate that a channel of 

 about 3,000 M. (1,610 Fm.) leads from the Pacific into Bering 

 Sea. A dotted line shows the possible location of the 3,000 M. 



