In 1901, the Sydney’s Evening News reported that scientists believe the break-off of Antarctic icebergs from glaciers is linked to volcanic activity underneath the Antarctic Continent
Icebergs in The Southern Ocean — Evening News (Sydney, NSW: 1869 – 1931), Saturday 14 December 1901, page 9
OFFICERS of the New Zealand Shipping Company’s steamer Rimutaka lately reported having seen 700 icebergs, one of which was four miles long, in the vicinity of Cape Horn. This led Dr. Ross to inquire of the Minister for Public Instruction if he would obtain from the Government Astronomer a report as to the effect (if any) the appearance of so large a number of icebergs in the Southern Ocean would have in bringing about any climatic variations or conditions of the continent of Australia in the near future or otherwise.
The worthy medico obtained the following reply: — The Government Astronomer reports as follows:
During 1895, 1896, and 1897 icebergs innumerable, off and on, were reported on the tracks of vessels from London to Australia. Some of these reached almost to the longitude of West Australia, and these years here were remarkably hot, i.e., 1895, 1896, and 1897. The great cold spell in New South Wales was in 1900.”
On September 4, 1895, Mr. Russell read a paper on this subject before the Royal Society of New South Wales. In this the Government Astronomer referred to the extraordinary’ occurrence within the previous eighteen months of icebergs between the Cape of Good Hope and Australia. Many years since, he said, Lieutenant Maury studied the subject, and found that to the north of latitude 50deg Antarctic icebergs most abounded between the meridians 15deg west and 55deg east.
Mr. John Towson, P.R.G.S., in his paper published by the British Board of Trade and Admiralty, called – ”Icebergs in the Southern Ocean,” and which discussed every record of icebergs in the Southern Ocean from the time of Captain Cook to 1858, alters the limit to 50deg west to 10deg east. The result of Mr. Russell’s own observations would make the limits 50deg west and 110deg east. According to Mr. Russell, from 1891 upwards to July, 1895, vessels bound for Australia via the Cape of Good Hope found icebergs east of the Cape. Many vessels saw forty or fifty a day, and others still more, and up to 150; and Mr. Russell thinks many of them came from the lee of Patagonia.
Admiral Fitzroy also favours this view, for he says (”Weather,” page 149):
Immediately round Cape Horn and the Falkland Islands ice seldom remains, as any that is drifted there is carried eastward by the current that always sets around the great southern promontory, and the south-easterly winds help this.”
With reference to the area between New Zealand and Cape Horn, Admiral Fitzroy said:
In the South Pacific, between 150deg and 100deg west longitude and 50deg to 60deg latitude, every ship that risks a passage through it finds numerous and some enormous masses of ice. Immense islands rather than Icebergs have been passed thereabouts, 800ft to 1000ft above the sea, and several miles in circumference.”
Mr. Russell found no record by Maury, Fitzroy, or Towson of Icebergs to the east of New Zealand, and yet from 1890 to 1895 they formed a conspicuous feature about the Chatham Isands. Lieutenant Maury and Towson referred to ”sudden accessions of ice bergs;” but Mr. Russell had found nothing to indicate a repetition in regular periods, and there was, in his opinion, no reason to suppose there was any such recurrence.
“The records showed,” said the Government Astronomer, ”such untold number of icebergs that it is difficult to believe that they have taken so many thousands of years to form, as some authorities demand. Vast as the Antarctic Continent is, it does not seem possible that room could be found on it for the building up gradually, from pre-Adamite times, all these multitudes of icebergs. When we trace them in the ocean, it is evident that they drift northwards, get into warmer water, where they begin to break up with tremendous noise — (the Cutty Sark, February 8, 1893, heard reports like that of an eighty-ton gun) — and grinding, which, aided by the solvent power of the water, destroys the iceberg in a comparatively short time. How then can they have taken so many thousands of years to make as some authorities demand?
Were the Antarctic region as large as the whole world, there would not be space to make the icebergs which we see in process of destruction in the ocean, if the origin of each iceberg was always back in pre-Adamite days.
When we come to look at these reports closely, we find the great majority of the icebergs are of moderate dimensions — 500ft to 2000ft in extreme dimensions — and such icebergs might, I think, be formed in comparatively short periods. Slow as the motion of solid ice is known to be, it does make a measurable progress from year to year; that progress depending upon the amount of snow, and the decline down which it is finding its way to the sea. But, taking an average glacier, it progresses a mile in from twenty to thirty years, and, therefore, the great majority of icebergs of the dimensions just given could be made in comparatively short periods. Some are, however, very much larger, and the number of icebergs seem to be vastly greater in some years than in others.
As an explanation of this, it has been, suggested that unusual falls of snow may account for it by accelerating the motion of the ice; but I think the circumstances forbid the acceptance of this view, because the motion of the glacier depends mainly upon the declivity down which it is descending, and that does not alter, and the piling up of snow could not in one year cause such a marked increase in the rate of flow as would be necessary to account for the enormous increase in numbers which appear from time to time, as, for instance, in 1854 and 1891.
There must evidently be a force sufficient to break off the icebergs, which are slowly forming on shore, and to do it at irregular periods, separated by many years. Such a force seems to reside in the volcanoes of the Antarctic Continent, when they burst forth in eruption and earthquake, and so shake the foreshores that the icebergs are broken off from the glaciers, and set adrift to float we know not where. This view derives some support from the character of the icebergs when outbursts occur, as at the end of 1854, and-again recently, for on each occasion there were great icebergs which only some convulsion of nature could set adrift.
One of these was reported by 21 ships in 1855. It was a solid mass of ice, measuring 60 miles on one side, 40 miles on another, and in the third side (for it was triangular) there was a great bay into which three vessels unconsciously sailed. Two got out by tremendous exertion, and the third became a total wreck. Again, on January 17, 1893, the ship Loch Torridon, in latitude 53deg 51min, longitude 46deg west, sailed for 50 miles along one side of an immense ice island, and the captain saw another estimated to be 1500ft high. On January 11, 1893, the ships Westdale and Strathcathro sailed, all unconscious of danger, into a horseshoe shaped bay in an iceberg. It was 20 miles deep, 10 miles across in the middle, and 4 miles wide at the entrance. The similarity of this ice-bound bay with the one seen in 1855, and another seen by Dampier in his voyages, is noteworthy, for they were all alike. It would seem as if there were some forming place — a mould — in which these icebergs are built up and held until some great eruption, sets them free.”
‘If,” says Mr. Russell, ”we accept the suggestion of the cause of sudden accession of icebergs here put forward, we have a cause known to be in operation there, and quite sufficient to account for the enormous number of icebergs, and also of the large dimensions of some of them at these times of outburst.”
It is noteworthy that the ice which came with the great outburst in 1854-1855, also disappeared quite suddenly, probably due to the prevalence of strong north-west winds over the Southern Indian. Ocean. (At (At the meeting of the Royal Society on October 6, 1897, Mr Russell read a second paper on the subject, in the course of which he said ‘that so far as the records go, we find that when there is a prevalence of north-west winds no ice is re-ported, and with southerly winds plenty of ice is reported. . . . A storm in the iceberg area travels to Australia in six of seven days, and the probability that the iceberg area has the same winds: that we have in Australia, only a few days earlier, is very strong indeed.
Mr. Russell suggested that vessels sighting ice bergs on a fine day, with a strong northerly or southerly wind, should stop the engines, and watch the berg carefully for three or four hours, to see if it does move with the wind, for as soon as the motion with the wind is definitely deter-mined by actual observation of the berg, it will be possible, by careful study of, the wind in South Africa and Australia, to forecast the position of icebergs between Africa and, Australia With some degree of exactness. In conclusion, the Government Astronomer said
It seems unnecessary to urge upon those most interested the importance of the experiments suggested. My investigations have convinced me that the icebergs do drift with the wind at a very appreciable rate, and there certainly are many risks, much anxiety, and loss of time, which might be, avoided if my suggestions prove to be facts, as I think, they will.”