The canyons In Profile A-B are probably deep notches cut Into the south wall of the 

 longitudinal depression and into its bordering inner shelf, the 130-fathom flat 

 topped crests between the notches . 



A brood, tongue-shaped trough extends southeast from just inside the shelf 

 break landward through Sulzberger Bay, where it finally disappears under the ice 

 shelf. This trough shown on Figure 2 and Profiles E-F and J-K (Fig. 4) is called 

 the transverse depression after Holtedahl (1958). The walls of the depression ap- 

 pear t^havecomparative I y moderate curving slopes, and the deeper parts of its 

 floor are between 550 and 650 fathoms. 



Shelf depressions also are found adjacent to the western coast of Edward VII 

 Peninsula (Fig. 2); further south the USS GLACIER recorded a near-shore depression 

 which is probably related to a north-south depression described by Crory, et al 

 (1962) that continues south under the Ross Ice Shelf parallel to and bordering the 

 Ross embayment . Other depressions similar to the longitudinal depressions off 

 Edward VII Peninsula undoubtedly exist along the northwestern shores of Guest 

 Island and Ruppert Coast (Fig. 2) . Although no sounding data were collected to 

 substantiate this, Byrd (1933) noted that thick icebergs floated freely when they 

 broke from ice cliffs off these shores and did not become grounded until they had 

 traveled some distance from shore. 



D. Shelf Ridges 



The submarine moraine-like ridges found on the continental shelf of the 

 eastern Ross Sea -Sulzberger Bay area are either transverse or parallel to the general 

 trend of the shoreline and, accordingly, will be referred to as transverse or longi- 

 tudinal ridges (Figs . 2 and 5) . 



The transverse ridge extending north from Cape Colbeck appears to be super- 

 imposed on the inner shelf, the longitudinal depression, and the outer shelf. As 

 shown by Profile A-B, Figures 2 and 3, the ridge is asymmetrical - its crest is 

 closer to its eastern edge. The shallowest sounding, 49 fathoms (shown on Figure 

 5), north of Cape Colbeck, was obtained by Roos (1937) near grounded icebergs. 



Another transverse ridge exten^ds westward from the western shore of Edward 

 VII Peninsula (Fig. 2). This ridge, like the other, appears to be superimposed 

 on the inner shelf, the depression, and the outer shelf. Its 70-fathom crest is 

 serrated by a series of deep, half-mile-wide notches. 



A longitudinal ridge, seaward of the longitudinal depression off the north 

 shore of Edward VII Peninsula (Fig . 2), was indicated by soundings made by 

 GLACIER in 1961-62 . This ridge appears to consist of two broad mounds aligned 



