DISCUSSION OF THE CARNEGIE SOUNDINGS 



The fact that the scientific program of the Carnegie 

 did not permit of running parallel lines of soundings 

 close together resulted in long single lines of soundings 

 with few intersections. Consequently the data collected 

 cannot be used alone for the construction of a bathymet- 

 ric chart, but can be used to modify existing charts 

 based on other data and in the construction of profiles 

 along the course of the vessel. Such profiles reveal 

 some of the major features of bottom relief and the 

 general depth level of the oceanic sections traversed. 



Attention may well be called to some of the features 

 brought out on the profiles. On profile no. 8 is to be 

 seen what has been named Merriam Ridge in about lati- 

 tude 25° south and longitude 82° west. Its location with 

 respect to the islands of San Felix and San Ambrosio 

 makes it seem probable that a submarine ridge extends 

 in a general northwest-southeast direction here, and 

 that the two islands are the high points of the ridge. 



On profile no. 9 at about latitude 15° south and long- 

 itude 98° west, Bauer Deep reaches a sharp depression 

 of about 1500 meters below the nearby bottom. Farther 

 to the west in this profile is the island of Tatakoto at 

 about longitude 138° 20' west. West of Tatakoto is 

 Amanu Island at about longitude 140° 45' west and west- 

 ward of this we see a platform extending from about 

 longitude 141° 40' west to about 142° 30' west. This is 

 possibly a part of the platform on which rests the island 

 of Tauere or St. Simeon, just to the north in about lati- 

 tude 17° 20' south. West of this platform in about lati- 

 tude 18° south and longitude 145° west two soundings 

 indicate the crossing of a ridge which is probably the 

 extension to the southeastward of the base of \naa or 

 Chain Island. In about longitude 148° west is Mehetia 

 Island with depths of more than 3000 meters between it 

 and Tahiti. Farther to the west in the approach to the 

 Samoan Islands, the base of Rose Island is discernible 

 and a depth of more than 3500 meters separates the is- 

 lands of Tutuila and Upolu. 



In profile no. 11 the steep eastern and western ap- 

 proaches to Wake Island are seen at about longitude 166° 

 40' east. From Wake Island westward to Guam the Car - 

 negie traversed an ocean whose bottom was previously 

 known to be very irregular and characterized by the sub- 

 marine mountains such as appear in this part of the pro- 

 file. Toward the western end of this profile the northern 

 arm of Nero Deep was crossed in about longitude 147° 

 20' east with soundings of 7846 and 7448 meters. 



At about 24° north latitude in profile no. 12 we see 

 Fleming Deep, in which the deepest of the Carnegie 

 soundings were taken, namely, 8323 and 8347 meters. 

 Soundings taken September 13 to 19, 1899, by the U.S.S. 

 Nero about 30 miles west of the Carnegie positions hint 

 at the existence of the deep but apparently were taken 

 well up on the western slope. It seems probable that the 

 Carnegie soundings also are west of the deepest part. A 

 sounding of 7575 meters shown on Japanese Hydrographic 

 chart no. 6080 at 23° 00' north latitude, 144° 55' east 

 longitude, is probably on the southern border of this 

 deep. Heavy weather (including two typhoons) produced 

 so much extraneous noise in the hydrophones that it was 

 impossible to take any soundings between about latitude 

 31° 40' north and latitude 33° 20' north. This was much 

 lamented, as during this period our course lay across 



the southern, and what is probably the deepest, part of 

 the extensive Tuscarora Deep. Farther north in this 

 profile, between about latitude 36° north and 37° north, 

 this deep was again crossed. 



A newly discovered submarine mountain is shown in 

 profile no. 13 at about latitude 46° 30' north and longi- 

 tude 169° 30' east. It is rather broad, but rises from 

 1500 to 2000 meters above the surrounding ocean floor. 



Between San Francisco and the Hawaiian Islands, 

 and shown in profile no. 14 at about longitude 127° 50' 

 west, is a submarine mountain which has been named 

 Hayes Peak. This mountain rises precipitously from 

 depths greater than 4000 meters to within 1400 meters 

 of the surface. The charts show a similar mountain 

 about 20 miles WSW1/2W of Hayes Peak. This would 

 suggest an error in position were it not probable that 

 many such submarine mountains exist in this vicinity. 



North of Honolulu, and shown in profile no. 16 at 

 about latitude 25° 40' north, is a rise which has been 

 named Ault Peak. Although it was far from being com- 

 pletely explored, the shallowest sounding over it gave a 

 depth of 2548 meters, indicating an elevation of more 

 than 2000 meters above the neighboring ocean bottom. 



In profile no. 21 the northeast and southwest ap- 

 proaches to Penrhyn Island are shown in about longitude 

 158° west. Similar approaches to Manahiki Island are 

 shown in about longitude 161° west with the trough be- 

 tween the two islands reaching a depth of 5899 meters. 

 Manahiki Island stands as a sharp peak on a broad plat- 

 form the depth of which is between 2500 and 3000 meters; 

 depths of more than 5000 meters separate it from the 

 Samoan Islands. 



Let us now consider how the soundings of the Car - 

 negie require changes in our previous conceptions of 

 the most probable course of the depth contours in the 

 ocean areas traversed. Some base map must be selected 

 for reference and, although it is not up to date in many 

 respects, the Monaco "Carte Gfinerale Bathym^trique 

 des Oceans" has been chosen as being most complete 

 and most generally available to hydrographers. Refer- 

 ence is hereafter made to this chart with two exceptions, 

 namely, the area between southern Greenland and New- 

 foundland, where the reader is referred to part 1 of the 

 Scientific Results of "The Marion expedition to Davis 

 Strait and Baffin Bay," Bulletin No 19, U. S. Treasury 

 Department, Coast Guard, Washington, 1932, and in the 

 region of the seas adjacent to Japan, where reference is 

 made to the Japanese Hydrographic Department chart no. 

 6080. 



On the Norwegian Sea slope and on the Iceland side 

 of the saddle in the Faroe-Iceland Ridge, soundings 64 

 and 65 indicate that the 500-meter contour line should be 

 moved somewhat to the northeast. On the southeastern 

 coast of Iceland, between longitudes 15° and 17° west, 

 the 1000-meter contour needs to be moved southward to 

 include soundings 75 and 76. The tongue of the 1000- 

 meter contour off Cape Reykjanes, Iceland, requires an 

 S-shape on its western side to pass between sounding 99 

 and the group 100, 101, and 102. The adjacent 2000- 

 meter contour southwest of here needs to be bent some- 

 what to the east to pass between soundings 107 and 108. 

 Following this same contour toward the south, another 

 S-pattern is embroidered on it, centered at about 58° 



149 



