6 DISCOVERY REPORTS 



schon J. G. Andersson zog aus der gefundenen Bodentemperatur von — i-6° bis 

 — i-8° diese Schlussfolgerung ". Similarly J. Rouch (1913, p. 28): "...a partir d'une 

 profondeur voisine de 500 metres, la temperature de l'eau de mer est constante et 

 assez basse, ce qui laisse supposer que le detroit de Bransfield forme un bassin special 

 ferme par un seuil dont la profondeur serait voisine de 500 a 600 metres". Also 

 G. Wiist (1926, p. 243): " ...das Bransfield-Meer. Dieses abgeschlossene Meeresbecken, 

 dessen grosste Tiefe wir auf unserem Kurse mit etwa 2000 m. feststellten, ist unterhalb 

 300 m. mit einem sehr kalten und fast homohalinen Wasser erfullt, das offenbar an den 

 Boschungen des Graham-Landes abgesunken ist. Der Temperaturunterschied 

 korrespondierender Tiefen innerhalb und ausserhalb des Beckens erreicht in 1000 m. 

 den hohen Betrag von 3*05° ". 



In February 1929 the R.R.S. 'William Scoresby' observed a temperature of i-ii° C. 

 at 1500 m. at St. WS 400, in 62 07' S, 62 33' W, i.e. just outside the strait, whilst 

 5 days previously at St. WS 385, inside the strait at 62 32' S, 57 55' W, a temperature 

 of — 1 -63° C. was recorded at the same depth. 



The above comments or results from four different sources show the very great con- 

 nection between the contours of the sea-bottom of this area and the peculiar hydro- 

 graphical conditions to be found there. 



Previous to the echo-sounding work of the German Atlantic Expedition in 1926 and 

 the soundings taken during the Discovery investigations in 1927, 1929, 1930 and 1931, 

 the bathymetric chart published in 1917 by O. Nordenskjold was probably the most 

 accurate. The Swedish South Polar Expedition in 190 1-2 had taken a line of soundings 

 between McFarlane Strait and Astrolabe Island, some soundings on the continental 

 shelf of Graham Land and some soundings to the north-east of the Bransfield Strait. 

 These soundings showed the presence of a longitudinal basin which was closed at the 

 north-east end by a rise of the sea-bottom to the common shelf depth of 400-500 m., to 

 fall again rapidly on the eastern side to the great ocean depths. The Deuxieme Expedi- 

 tion Antarctique Francaise, 1908-10, confirmed the existence of the basin in the 

 Bransfield Strait. The echo-soundings of the German Atlantic Expedition, 1925-7, 

 showed the rise of the continental shelf of the South Shetland Islands from the great 

 ocean depths of the Drake Strait. According to O. Holtedahl (1929, p. 95) these 

 soundings of the German Atlantic Expedition showed the existence of very marked 

 planes of abrasion, thus proving a former higher level of the land and consequently an 

 increased width of the South Shetland Islands in the past. The echo-soundings of the 

 ' Meteor ' again showed the presence of a deep basin in the Bransfield Strait, with an 

 indication of a rise in the sea-bottom to the north, some 13 miles west-south-west of 

 Elephant Island and approximately 12 miles north of Aspland Island. 



Such was the state of knowledge when our own observations began. Lines of 

 stations from King George Island and Livingston Island across the strait to Trinity 

 Peninsula, and between Smith Island and Brabant Island were worked in 1927, 1929 

 and 1930, and the sounding data from these stations were augmented by over 1400 echo- 

 soundings in this area by R.R.S. 'Discovery II'. In the bathymetric chart, Fig. 2, all 



