Hostname: page-component-7479d7b7d-q6k6v Total loading time: 0 Render date: 2024-07-11T07:45:09.309Z Has data issue: false hasContentIssue false

Some Notes on the Structure and Flow of Ice

Published online by Cambridge University Press:  01 May 2009

L. Hawkes
Affiliation:
Reader in Geology, Bedford College, University of London.

Summary

Natural compact ice is not wholly crystalline. Salt solution is present in glacier ice at temperatures down to −21·72°, and is probably located at the intergranular boundaries. The proportion of brine is normally very small, but becomes considerable near 0°.

The special mechanical properties at the intergranular contacts, the “Hugi effect” on melting, the phenomena of regelation, and the infra-red absorption, indicate that the molecules at these contacts are in the amorphous state. This may be the case in ice free from salts.

Internal flow takes place by relative displacement of crystalline portions by means of slip:—

1. along the basal planes of the crystals,

2. along intergranular surfaces,

3. along fracture surfaces within the individual crystals.

Processes 2 and 3 are facilitated by the presence of liquid at the surfaces of slip, and it is the regelation power of this liquid which preserves the cohesion of the deformed masses.

The liquefaction at points of compression, transference of the liquid, and its congelation elsewhere, is an important factor in the formation of compact ice from névé, but is of secondary importance in the flow of compact ice.

The processes by which ice suffers deformation are those which operate in the flow of all crystalline masses, the comparative ease with which it is deformed being an instance of the weakness of rocks near their melting temperatures. Ice at hundreds of degrees below its melting point would compare in strength and hardness with the other crystalline rocks which exist under like temperature conditions in the outer part of the earth's crust.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 1930

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

page 111 note 1 Tyndall, J., Glaciers of the Alps, 1860, p. 311.Google Scholar

page 111 note 2 Hess, H., Die Gletscher, 1904, p. 125.Google Scholar

page 111 note 3 See Deeley, R. M. and Parr, P. H., Phil. Mag., 1914, p. 168.Google Scholar

page 112 note 1 All temperatures are given in degrees centigrade.

page 112 note 2 Tammann, G., The States of Aggregation, 1925, fig. 77, p. 159.Google Scholar

page 112 note 3 Thomson, J., B.A. Abstracts, 1857, pp. 3940.Google Scholar

page 112 note 4 See for example, Pirsson, L. V., Text Book of Geology, pt. i, 1920, p. 132.Google Scholar

page 112 note 5 Thomson, J., Proc. Roy. Soc., xi, 1861, pp. 473–4.Google Scholar

page 112 note 6 Johnston, J. and Adams, L. H., Am. Journ. Sci., xxxv, 1913, p. 214.Google Scholar

page 112 note 7 Chamberlin, T. C., Dec. Pub. Univ. of Chicago, ix, 1904, p. 194.Google Scholar

page 113 note 1 McConnel, J.C., Proc. Roy. Soc., xlix, 1891, pp. 323–43.Google Scholar

page 113 note 2 Mügge, O., Neues Jahrb. f. Min. Geol., ii, 1895, pp. 211–28.Google Scholar

page 113 note 3 Tarr, R. S. and Rich, J.L., Zeit. f. Gletscherk., vi, 19111912, p. 247.Google Scholar

page 113 note 4 Deeley, R. M., Geol. Mag., 1910, pp. 112–14.CrossRefGoogle Scholar

page 113 note 5 Wright, C. S. and Priestley, R. E., Brit. Ant. Expd., “Glaciology,” 1922, p. 79.Google Scholar

page 113 note 6 Finlayson, J. N., Canadian Engineer, liii, 1927, p. 101.Google Scholar

page 114 note 1 Buchanan, J. Y., Proc. Roy. Soc. Edin., xiv, 1887, pp. 129–47;Google Scholar and Buchanan, J. Y., Proc. Roy. Inst., xix, 19081910, pp. 243–76.Google Scholar

page 115 note 1 Person, C. C., Compt. Rend., xxx, 1850, pp. 526–8.Google Scholar

page 115 note 2 Smith, A. W., Phys. Rev., xvii, 1903, p. 223.Google Scholar

page 115 note 3 Tarr, R. S. and von Engeln, O. D., Zeit. f. Gletscherk., ix, 19141915, p. 128.Google Scholar

page 115 note 4 Whiteman, W. G., Am. Journ. Sci., xi, 1926, pp. 126–32.CrossRefGoogle Scholar

page 115 note 5 Buchanan, J. Y., Scot. Geogr. Mag., xxviii, 1912, p. 186.Google Scholar

page 115 note 6 Hugi, F. J., Edin. New Phil. Journ., x, 18301831, pp. 337–8.Google Scholar

page 115 note 7 A good summary of the evidence for the presence of intergranular brine is given by Tarr and von Engeln, op. cit., pp. 125–32.

page 116 note 1 Tryndall, J., op. cit., pp. 354–61.Google Scholar

page 116 note 2 Quincke, G., Proc. Roy. Soc., A, lxxvi, 1905, p. 438.Google Scholar

page 116 note 3 Op. cit., p. 435.

page 116 note 4 Collins, J. R., Phys. Rev., xxvi, 1925, pp. 771–9.CrossRefGoogle Scholar

page 116 note 5 Plyler, E. K., Journ. Opt. Soc. Amer., ix1, 19241925, pp. 553–4.Google Scholar

page 117 note 1 Faraday, M., Proc. Roy. Soc., x, 1860, p. 441.Google Scholar

page 117 note 2 See Faraday, M., Researches in Chemistry and Physics, 1859, p. 374, andGoogle Scholar Barnes, H. T., Ice Formation, 1906, pp. 8392.Google Scholar

page 118 note 1 Op. cit., p. 339.

page 118 note 2 See Howorth, H. H., Proc. Man. Lit. Phil. Soc., iv, 18901891, pp. 80–5.Google Scholar

page 118 note 3 See Jeffries, Z. and Archer, R. S., Chem. and Met. Eng., xxvi, 1922, p. 410.Google Scholar

page 118 note 4 Wright, Cf. and Priestley, , op. cit., p. 118.Google Scholar

page 118 note 5 Op. cit., p. 434.

page 118 note 6 Op. cit., p. 124 and p. 107.

page 119 note 1 Op. cit., p. 90.

page 119 note 2 Op. cit., p. 106. In view of these observations it is surprising to read: “The flow … is not due to crushing or brecciation, as the resultant ice mass is coherent and glassy,” p. 92.

page 119 note 3 Deeley, op. cit., p. 435. It may be noted that Forbes (The Theory of Glaciers, 1859, p. 47Google Scholar) erroneously considered the blue veins to represent the “bruised” ice. For illustrations of the intimate structure of veined ice, see Deeley, Geol. Mag., 1895, pp. 156–8.

page 119 note 4 Tarr and von Engeln, op. cit., p. 92.

page 119 note 5 Chamberlin, R. T., Journ. Geol., xxxvi, 1928, p. 21.Google Scholar

page 119 note 6 Beilby, G., Aggregation and Flow of Solids, 1921, p. 189.Google Scholar

page 120 note 1 It might be possible to demonstrate the application of Beilby's theory to ice, by showing that relegation occurs when smoothed surfaces of dry ice are rubbed together at less than the melting pressure.

page 120 note 2 Beilby, , op. cit., pp. 199200.Google Scholar

page 120 note 3 Hawkes, L., Nature, cxxiv, 1929, pp. 225–6.CrossRefGoogle Scholar

page 120 note 4 Chamberlin, T. C., op. cit., p. 194.Google Scholar

page 121 note 1 Barnes, H. T., Ice Engineering, 1928, p. 333. This work contains a valuable bibliography of about 350 entries.Google Scholar

page 121 note 2 Chamberlin, T. C., op. cit., p. 201.Google Scholar See also Chamberlin, T. C. and Salisbury, R. D., Geology: Processes and their Results, 1909, p. 313.Google Scholar

page 121 note 3 Deeley, op. cit., 1910, p. 436.Google Scholar

page 122 note 1 Hess, , op. cit., pp. 128–38.Google Scholar

page 122 note 2 Tyndall, , op. cit., pp. 419–21.Google Scholar

page 122 note 3 The rapid diminution in velocity near the end of the glacier gives an illusory appearance of compression, for it is to be correlated with a reduction in thickness, the faster moving upper layers being melted away.