V.—The Thickness of the Ice-Cap in the various Glacial Periods

In estimating the maximum load which pressed upon the northern type of Glacial (Dwyka) Conglomerate in Prieska, Cape Colony, I assumed that the calculations of Sir Wyville Thomson and Bernacci were correct, and that the greatest column of ice that could exist on the earth's surface was from 1,400 to 1,600 feet high. This limit, however, is by no means accepted by European glacialists, who, though they do not go as far as Dr. Croll in assuming thicknesses of 120,000 feet, yet see no reason why there could not have been ice-sheets 5,000 feet thick. The publication of Captain Scott's narrative of the voyage of the “Discovery” has given us certain definite data from the Antarctic which enable the case for the 1,600 feet maximum to be put with more confidence, and I will endeavour in the present paper to state the main lines of the argument. The question is of importance not only to us in South Africa with our two Palæozoic ice-ages, but to all geologists, as it affects the problem of the earth's equilibrium. To give a recent example, Professor Penck, in describing the Bodensee, discusses whether the weight of ice pouring down from the Alps in a sheet 3,600 feet thick may not have had some effect in producing a sinking in the earth's crust.

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IV.—Notes on “The Great Ice Age” in Relation to the Question of Submergence

Geological Magazine ◽

10.1017/s0016756800129784 ◽

1895 ◽

Vol 2 (9) ◽

pp. 402-405

Author(s):

Dugald Bell

Keyword(s):

Earth’S Crust ◽

Ice Age ◽

General Interest ◽

Glacial Erosion ◽

Glacial Epoch ◽

Earth's Crust ◽

Glacial Periods

Leaving those local matters, there is a point of some general interest, suggested by several passages of Dr. Geikie's work, which we should like briefly to notice before laying it aside. It is in regard to those repeated depressions and re-elevations of the land which he still favours in connection with the Glacial epoch. Dr. Geikie's latest “scheme” of that epoch seems to include at least five Glacial and four inter-Glacial periods, accompanied by submergences and re-elevations to the extent of between 500 and 600 feet—the maximum being for the present restricted to that amount. Frankly, we confess ourselves unable to see the proofs for so many Glacial and inter-Glacial periods, of which, if they did occur, it would apparently be impossible—on the author's own premises as to glacial erosion—now to discover any traces. Apart from this, we might remark on the inherent improbability of such extensive oscillations of the earth's crust having happened in recent geological times, without leaving more distinct evidence of themselves than the very scanty and doubtful deposits which we have been considering.

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I.—The Antarctic Ice-cap

Geological Magazine ◽

10.1017/s0016756800118989 ◽

1906 ◽

Vol 3 (12) ◽

pp. 529-534

Author(s):

H. T. Ferrar

Keyword(s):

Ice Sheet ◽

Ice Caps ◽

Ice Cap ◽

Main Support ◽

Glacial Periods ◽

The Antarctic ◽

Geological Magazine

In a recent number of the Geological Magazine, Dec. V, Vol. III, March, 1906, p. 120, there is an article by Prof. E. H. L. Schwarz which deals with the thickness of ice-caps during the various Glacial periods. At the outset Professor Schwarz takes the data furnished by Captain Scott's narrative of the voyage of the “Discovery” as the main support of the physicists' contention that an ice-sheet cannot exceed 1,600 feet in thickness.

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International cooperation of S. I. Subbotin Institute Geophysics, NAS of Ukraine for 2010—2020

Geofizicheskiy Zhurnal ◽

10.24028/gzh.v43i3.236390 ◽

2021 ◽

Vol 43 (3) ◽

pp. 205-226

Author(s):

V. I. Starostenko ◽

O. M. Rusakov ◽

A. I. Yakimchik

Keyword(s):

Antarctic Peninsula ◽

Age Distribution ◽

Earth’S Crust ◽

Ukrainian Shield ◽

Donets Basin ◽

Mutual Position ◽

Crust And Upper Mantle ◽

Eastern Carpathians ◽

Earth's Crust ◽

The Antarctic

The geological structure of the lithosphere of the main tectonic structures has been refined for the territory of Ukraine and adjacent regions of Slovakia, Poland, Romania, Russia, as well as Bulgaria, the Antarctic Peninsula (West Antarctica) and Southeast Asia, and new data have been obtained on geophysical impacts that can affect the environment. A geodynamic scenario has been developed for the formation of large-scale folding of the Fore- Dobrudzja Trough, the South Ukrainian monocline and the Ingul block of the Ukrainian Shield, caused by tectonic events associated with the closing of the Paleotethys and Neotethys oceans in the Mesozoic. In the Pripyat-Dnieper-Donets Basin, the structure of the earth’s crust and upper mantle can reflect different intensities of rifting, from its passive stage in the Dnieper Graben to active rifting in the Pripyat Trough. An analysis of the geoelectric structure of the Earth’s crust in the Ukrainian Eastern Carpathians indicates that seismic events occur mainly in resistive solid rock domainswhich surrounded by aseismic high conductive zones consisting of at least partially melted material. The present-day mutual position of the Ukrainian shield and Fennoscandia stabilized 1720—1660 Ma. The age, distribution, orientation and composition have been studied for the LatePalaeoproterozoicdykes in the Volyn, Ingul and Azov blocks of the Ukrainian Shield. Eastern Crimea and the Sorokin Trough are fragments of a tectonic wedge formed after the Paleocene. The geothermal conditions of the Intra-Carpathian region are due to subduction during the closure of the Pannonian sea basin and the collisional interaction of the Eurasian plate with the microplates system of this region. In Bulgaria, most earthquakes occur outside high-resistive domains. The tectonic stages are reconstructed for the formation of the northern part of the Antarctic Peninsula in the Mesozoic-Cenozoic. The relationship has been established between the geomagnetic field and climate change, with it being different for the Northern and Southern Hemispheres. The results have been obtained within the framework of 25 international projects and 6 temporary international target teams of S. I. Subbotin Institute of Geophysics, NAS of Ukraine consisting of researchers from 23 countries. The results are presented in 53 publications, 38 of which are indexed in the Web of Scienct database, and 32 papers are published in 20 international journals and special publications of 10 countries with different impact factors (from 0,101 to 4,214), whose average impact factor is 3,341, and the total one is 66,815.

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Cauldron subsidence and subglacial floods

Annals of Glaciology ◽

10.3189/172756407782282561 ◽

2007 ◽

Vol 45 ◽

pp. 163-168 ◽

Cited By ~ 21

Author(s):

G.W. Evatt ◽

A.C. Fowler

Keyword(s):

Ice Sheets ◽

Ice Sheet ◽

Beam Theory ◽

Volcanic Eruptions ◽

Subglacial Lake ◽

Ice Cap ◽

Ice Surface ◽

Flood Discharge ◽

The Antarctic ◽

Ice Cauldrons

AbstractIce cauldrons are depressions which form at the surface of ice sheets when an underlying subglacial lake empties, in particular when subglacial volcanic eruptions occur. Notable examples of such cauldrons occur on the surface of the Vatnajökull ice cap in Iceland. More generally, cauldrons will form when a subglacial lake empties during a jökulhlaup. The rate of subsidence of the ice surface is related to the rate at which the subglacial water empties from the lake. We use a viscous version of classical beam theory applied to the ice sheet to determine the relation between the subsidence rate and flood discharge. We use the results to make inferences concerning ring fracture spacings in cauldrons, the consequent effect on flood discharge dynamics and the likely nature of subsidence events in the Antarctic Ice Sheet.

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