HEIGHT AND POSITION OF MOUNT ST. ELIAS.
The height and position of Mount St. Elias have been measured several times during the past century with varying results. The measurements made prior to the expedition of 1890 have been summarized and discussed by W. H. Dall, of the United States Coast and Geodetic Survey, and little more can be done at present than give an abstract of his report.
The various determinations are shown in the table below. The data from which these results were obtained have not been published, with the exception of the surveys made by the United States Coast Survey in 1874, printed in report of the superintendent for 1875.
Height and Position of Mount St. Elias.
| Date. | Authority. | Height. | Latitude. | Longitude W. |
| 1786 | La Pérouse | 12,672 feet | 60° 15' 00" | 140° 10' 00" |
| 1791 | Malaspina | 17,851 feet | 60° 17' 35" | 140° 52' 17" |
| 1794 | Vancouver | —— | 60° 22' 30" | 140° 39' 00" |
| 1847 | Russian Hydrographic Chart 1378 | 17,854 feet | 60° 21' 00" | 141° 00' 00" |
| 1847 | Tebenkof (Notes) | 16,938 feet | 60° 22' 36" | 140° 54' 00" |
| 1849 | Tebenkof (Chart VII) | 16,938 feet | 60° 21' 30" | 140° 54' 00" |
| Buch. Can. Inseln | 16,758 feet | 60° 17' 30" | 140° 51' 00" | |
| 1872 | English Admiralty Chart 2172 | 14,970 feet | 60° 21' 00" | 141° 00' 00" |
| 1874 | U. S. Coast Survey | 19,500 ±400 | 60° 20' 45" | 141° 00' 12" |
All of the figures given in the table have been copied from Dall's report, with the exception of the position determined by Malaspina; this is from a report of astronomical observations made during Malaspina's voyage, which places the mountain in latitude 60° 17' 35" and longitude 134° 33' 10" west of Cadiz.36 Taking the longitude of Cadiz as 6° 19' 07" west of Greenwich, the figures tabulated above are obtained.
36 Ante, p. 65.
It was intended that Mr. Kerr's report, forming Appendix B, should contain a detailed record of the triangulation executed last summer, but a careful revision of his work by a committee of the National Geographic Society led to the conclusion that the results were not of sufficient accuracy to set at rest the questions raised by the discrepancies in earlier measurements of the height of Mount St. Elias; and as the work will probably be revised and extended during the summer of 1891, only the map forming plate 8 will be published at this time. Some preliminary publications of elevations have been made, but these must be taken as approximations merely.37
37 The shore-line of the map, plate 8, and the positions of the initial points or base-line of the triangulation are from the work of the United States Coast Survey. The extreme western portion is from maps published by the New York Times and Topham expeditions. All the topographic data are by Mr. Kerr, and all credit for the work and all responsibility for its accuracy rest with him. The nomenclature is principally my own, and has been approved by a committee of the National Geographic Society.
By consulting the map forming [plate 8] it will be seen that Mounts Cook, Vancouver, Irving, Owen, etc., are not in the St. Elias range. Neither do they form a distinct range either topographically or geologically. Each of these mountains is an independent uplift, although they may have some structural connection, and are of about the same geological age. Mount Cook and the peaks most intimately associated with it are composed mainly of sandstone and shale belonging to the Yakutat system. Mounts Vancouver and Irving are probably of the same character, but definite proof that this is the case has not been obtained.
The St. Elias uplift is distinct and well marked, both geologically and topographically, and deserves to be considered as a mountain range. The limits of the range have not been determined, but, so far as known, its maximum elevation is at Mount St. Elias. The range stretches away from this culminating point both northeastward and northwestward, and has a well-marked V-shape. The angle formed by the two branches of the range where they unite at Mount St. Elias is, by estimate, about 140°. Each arm of the V is determined by a fault, or perhaps more accurately by a series of faults having the same general course, along which the orographic blocks forming the range have been upheaved. The structure of the range is monoclinal, and resembles the type of mountain structure characteristic of the great basin. The dip of the tilted blocks is northward.
The crest of the St. Elias range, as already stated, is composed of schists which rest on sandstone, supposed to belong to the Yakutat system. The geological age of the uplift is, therefore, very recent. The secondary topographic forms on the crest of the range have resulted from the weathering of the upturned edges of orographic blocks in which the bedding planes are crossed by joints. The resulting forms are mainly pyramids and roof-like ridges with triangular gables. Extreme ruggedness and angularity characterize the range throughout. There are no rounded domes or smoothed and polished surfaces to suggest that the higher summits have ever been subjected to general glacial action; neither is there any evidence of marked rock decay. Disintegration of all the higher peaks and crests is rapid, owing principally to great changes of temperature and the freezing of water in the interstices of the rock; but the débris resulting from this action is rapidly carried away by avalanches and glaciers, so that the crests as well as the subordinate features in the sculpture of the cliffs and pyramids are all angular. The subdued and rounded contour, due to the accumulation of the products of disintegration and decay, the indications of the advancing age of mountains, are nowhere to be seen. The St. Elias range is young; probably the very youngest of the important mountain ranges on this continent. No evidences of erosion previous to the formation of the ice-sheets that now clothe it have been observed. Glaciers apparently took immediate possession of the lines of depression as the mountain range grew in height, and furnish a living example from which to determine the part that ice streams play in mountain sculpture.