REPORT ON SOUNDINGS TAKEN DURING 

 THE DISCOVERY INVESTIGATIONS, 



1926-1932 



By H. F. P. Herdman, m.Sc. 



(Plates XLV-XLVII; charts 1-7; text-figs. 1-5) 



INTRODUCTION 



THIS report covers all the oceanic soundings taken during the course of the Discovery 

 Investigations from 1926 until April, 1932, in the following areas: 



(i) In the Scotia Sea and surrounding waters from 51° to 62^ S latitude between 20° 

 and 70° W longitude. 



(ii) In Bransfield Strait, the South Shetland Islands and the Palmer Archipelago. 



(iii) In the Bellingshausen Sea. 



In the first area are included intensive series of soundings round South Georgia and 

 the Shag Rocks and some of the soundings taken during the running survey of the 

 South Sandwich Islands in 1930. The soundings have been obtained by the R.R.S. 

 'Discovery' in 1926 and 1927, by the R.R.S. 'William Scoresby' in the years 1926-31 

 and from 1930 onwards by the R.R.S. 'Discovery II'. The majority of the soundings 

 have been taken by the last-named ship and by the echo method. In the detailed discussion 

 of these soundings prominence has mainly been given to those taken in oceanic waters. 

 Inshore soundings taken round the South Sandwich Islands are included in the recently 

 published report ^ on that group of islands. Intensive soundings in the bays and harbours 

 of South Georgia have also been omitted, as they are included in the report on the survey 

 operations round South Georgia by Lt.-Cmdr. Chaplin.^ 



In the ' Discovery' and the ' William Scoresby' difiiculty was sometimes experienced 

 in obtaining good wire soundings owing to the impossibility of keeping the sounding 

 wires vertical in bad weather, and for this reason not all of their soundings can be 

 accepted. In the ' Discovery II ', however, it was possible to obtain reliable wire sound- 

 ings in moderately bad weather by keeping the ship head-to-wind and steaming slowly 

 ahead whenever necessary to correct the "stray" on the wire. Since echo soundings, 

 however, can be taken every few minutes, and usually without stopping, the wire method 

 was latterly abandoned. Approximately 10,000 echo soundings were obtained between 

 February 1930 and May 193 1, and of these the greater number were taken between 

 December 1930 and March 1931. During the season 1931-2 approximately 2000 more 



1 Kemp and Nelson, The South Sandwich Islands, Discovery Reports, iii, pp. 133-98 ('930- 



2 Chaplin, Narrative of Hydrographic Survey Operations in South Georgia and the South Shetland 

 Islands 1926-30, Discovery Reports, iii, pp. 297-344 (1932)- 



