TIERRA DEL FUEGO TO THE SHAG ROCKS 219 



results are shown in the form of a contoured chart of the South Georgia — South Sand- 

 wich area, which gives the position of the soundings but no actual depths, and a section 

 drawn across the South Sandwich Deep. Stocks uses the uncorrected (unreduzierte 

 Werte) soundings of the 'Meteor' and assumes that the echo soundings of the 

 ' Discovery II ' are also uncorrected. As already explained, however, all the ' Discovery 

 II ' echo soundings have been fully corrected. Stocks noted that the Deep extended to 

 a position farther west than the 'Meteor's' observations would tend to show, and 

 pointed out the bearing of the new facts on Suess' theory. A bathymetric chart of 

 the Antarctic and sub-Antarctic areas embodying these results was published by the 

 American Geographical Society in 1929.^ This chart shows the South Sandwich Deep, 

 and although on a very small scale, gives an accurate representation of the bathymetric 

 conditions in the Scotia Sea as then known. 



DETAILED ANALYSIS OF THE VARIOUS SECTORS 

 OF THE SCOTIA ARC 



TIERRA DEL FUEGO TO THE SHAG ROCKS 



(Plate XLV, Charts 1,2,3) 



It is now generally accepted that if the Andes are continued on towards South Georgia 

 the continuation must He through the Burdwood Bank, and our soundings are in definite 

 support of this theory. A distance of 500 miles separates the eastern end of the Burdwood 

 Bank from the Shag Rocks, and it will be seen from the bathymetric chart of the Scotia 

 Sea (Plate XLV) that a well-defined submarine ridge can be traced by means of the 2000 

 and the 3000 m. contours for nearly the whole distance. There appears to be a break of 

 approximately 60 miles from about 47° W to about 49° W, but further soundings to the 

 north of the line on which the present contours are based may show that the ridge is 

 continuous. The ridge is much more sharply defined to the west of this gap, there being 

 two well-marked areas where the soundings are considerably under 1000 m. The 

 minimum sounding in the largest of these areas was 368 m. in a position approximately 

 53° 55' S, 52° 25' W and in the other area, 594 m. in approximately 53° 28' S, 49' 51' W. 



Georgia is through the Falkland Islands, whereas an examination of the contours in Plate XLV of this report 

 will show that the shelf is definitely continued through the eastern end of the Burdwood Bank. 



(ii) In the bathymetric chart (Fig. 36) given by Stocks, a long ridge, parallel to the main arc, is shown as 

 extending from a point north of South Georgia to approximately 300 miles east of the South Sandwich 

 Islands. The depth of water on the ridge is shown as under 3000 m. The evidence for the existence of this 

 ridge appears to be very slender, for apart from the bank shown to the north of Cape Crewe, South Georgia, 

 only two other soundings are mentioned. One of these is a Lucas depth of 2744 m. obtained by the R.R.S. 

 'Discovery ' in February' 1926, in a position 51° 55' S, 32° 27!' W, the other is an echo sounding of 1800 m. 

 obtained by the ' Meteor ' in the same month to the east of the South Sandwich Deep. From our bathymetric 

 plate (Plate XLV) it will be seen that subsequent soundings leave no doubt as to the non-existence of this ridge. 



(iii) North of the South Orkney Islands Stocks has shown another ridge, parallel to the main one, the 

 existence of which is not supported by the recent lines of echo soundings obtained by the 'Discovery II'. 



1 Bathymetric map of the Antarctic (South Atlantic, Indian and Pacific Oceans) compiled by the Amencan 

 Geographical Society of New York, 1929. 



