2 Dr. John Ball— The Gulf of Suez. 



observations were not possible at present, it occurred to me that 

 something in the way of evidence might be gathered from a careful 

 study of soundings in the gulf. As one of the world's great highways 

 of commerce, the Gulf of Suez has been thoroughly sounded by the 

 British Admiralty, and the Gulf of Akaba and the Red Sea have 

 likewise been subjected to sounding observations, though of a less 

 degree of closeness. I therefore took the large-scale Admiralty chart 

 of the Gulf of Suez, 1 and, using the soundings as a guide, drew in the 

 contours of the sea-bottom at 10 fathom intervals. I also examined 

 the smaller-scale chart 2 on which the Gulf of Akaba and the north 

 part of the lied Sea are shown, and compared the soundings in these 

 parts with those of the Gulf of Suez. The results furnish, I think, 

 a strong argument for the erosive origin of the Gulf of Suez. 3 



The first striking conclusion from an examination of the charts is 

 the extreme shallowness of the Gulf of Suez as compared with the 

 Gulf of Akaba and the lied Sea. The deepest sounding in the Gulf of 

 Suez is a solitary one of 63 fathoms south-east of the Island of Jubal, 

 and even this is a very local deepening, 4 for there is no sounding 

 indicating a depth of over 50 fathoms at any other point inihe gulf; 

 while the Gulf of Akaba is a deep trough with a maximum depth of 

 over 700 fathoms, and the Red Sea, even close south of the Gulf 

 of Suez, goes down to over 600 fathoms. The remarkable contrast 

 between the Gulfs of Suez and Akaba in regard to depth is shown 

 in the transverse section across the two gulfs, drawn to a natural scale 

 in Fig. 1. A subsidence of only 100 metres, which is nothing more 

 than can be accounted for by secular oscillation of the earth's crust, 

 such as is known to be going on in many parts of the world, would 

 leave the Gulf of Suez high and dry, while the Gulf of Akaba and the 

 Red Sea would be but little altered in outline, and would remain very 

 deep seas. Further, it will be seen from the longitudinal sections, 

 shown in Fig. 2, that while in the case of the Gulf of Suez there 

 is a gradual fall to the greatest depth at the mouth, and a final huge 

 drop to the Red Sea, in the case of the Gulf of Akaba we have 

 a trough with its greatest depth near the centre, and a transverse 

 ' horst ' separating that trough from the Red Sea. Can anyone 

 conclude that the two gulfs have a like origin ? To explain so deep 

 a trough as the Gulf of Akaba, devoid of outlet for over a kilometre 

 of its depth, a local subsidence may well be invoked, more especially 

 as it forms the geographical continuation of the Jordan Yalley, as 

 to whose origin in a trough subsidence there can, I suppose, be no 

 doubt. Rut the Gulf of Suez is an entirely different matter. "When 

 we realize that the Gulf of Suez is neither parallel to, nor a prolongation 



1 Admiralty Chart No. 757, revised to 1908. 



2 Red Sea Sheet No. 1, Admiralty Chart No. 8a, revised to 1897. 



3 It is remarkable that these same charts appeared to Mr. Barron and Dr. Hume 

 to support the idea of a trough-fault origin for the gulf, which is just what I consider 

 the charts disprove. See Topography and Geology of the Eastern Desert of Egypt, 

 Central Portion, Cairo, 1902, p. 213. My colleagues would, I think, have been 

 driven to an opposite conclusion had they drawn in the contours of the entire gulf, or 

 constructed a section across it to a natural scale. 



4 Such local deepenings occur in many river valleys, usually in consequence of 

 a, waterfall ; an example occurs in the Nile Valley below the First Cataract. 



