Tuesday, August 23, 2011

The subglacial fjords in Antarctica

Earlier this year, new data from ice-penetrating radar revealed a complex landscape of mountains and fjords deep beneath the Antarctic ice in the vicinity of Wilkes Land (east Antarctica).

A team of researchers from the University of Texas, the University of Edinburgh, the Australian Antarctic Division, and the Antarctic Climate and Ecosystems Cooperative Research Centre published a letter in the scientific journal Nature entitled "A dynamic East Antarctic ice sheet suggested by ice-covered fjord landscapes." In the abstract to that article, they wrote that "The identification of this fjord landscape, based on new data from ice-penetrating radar, provides an improved understanding of the topography of the Aurora Subglacial Basin and its surroundings, and reveals a complex surface sculpted by a succession of ice-sheet configurations substantially different from today’s."

This article from the BBC News provides some close-up of the topographic map of the fjord channels, buried under 3,000-plus feet of ice and below today's sea levels. That article quotes one of the team members, Professor Martin Siegert of the University of Edinburgh, saying:
The modern ice sheet couldn't possibly have done this; it has to have been the consequence of an ice sheet that was much smaller than today's. Comparing our data with geomorphological evidence from other regions of the world, we can be pretty confident that these fjords were formed by fast-flowing ice at the edge of the ice sheet. It's the first evidence we have of how the ice was in phases of growth and retreat as it marched across this subglacial basin to form the ice sheet we recognise today.
In their abstract to the article published in Nature, the scientists surmise that the ice sheet probably began forming about 34 million years ago, and then went through numerous cycles of advance and retreat (up to thirty such cycles) for the next 20 million years.

Of course, these conjectures are based upon the assumptions of conventional geology, which argue that Antarctica has been covered by its present sheet of solid ice for millions of years -- long before the arrival of modern man. We have already discussed how the hydroplate theory of Dr. Walt Brown -- which explains numerous aspects of the earth more satisfactorily than do conventional theories, and which is particularly helpful in explaining some of the mysterious evidence surrounding Antarctica -- proposes a different mechanism for the origin of a past ice age and the ice now covering Antarctica.

In this previous post, we noted that Dr. Brown argues that in order to achieve an ice age, heavy precipitation over cold continents would be necessary. Warm oceans could provide such heavy precipitation, but the conditions that would yield warm oceans and cold continents are difficult to envision under the conventional uniformitarian theories prevalent today. However, Dr. Brown's hydroplate theory envisions warm oceans immediately after the draining of the floodwaters, as well as higher and colder continents than we have today. The continents would have been higher because after their initial slide and thickening, they would not yet have sunk down into the mantle under their increased weight, and thus the sea levels were also lower than today (note that the recent subglacial radar findings also indicate that the oceans were much lower when these fjords were carved, since they are below today's sea level; previous posts have discussed other evidence for lowered oceans and the way this evidence supports the hydroplate theory more than it does conventional theories: see here and here). The oceans would have been warmer as well, due primarily to the energy released during the sliding of the hydroplates. Thus, for some centuries after the flood, the conditions would have been conducive to heavy cloud cover, precipitation as moist air rose over cold continents, and precipitation in the form of snowfall, which would have led to the formation of ice and advancing glaciers.

Amazingly, there are several medieval maps which appear to depict Antarctica with deep fjords and mountains. This fact is amazing on several levels, not least of which being the fact that Antarctica was not known to modern navigators in the west until the nineteenth century. Even more startling is the fact that many of the coastlines and other details on these maps of Antarctica appear to depict a continent not covered by ice -- or, to be more accurate, to depict it when ice probably covered much of the interior but did not cover the coastline the way it does today.

Among these maps are the Piri Re'is map of 1513 (shown above -- the coastline reputed to be that of Antarctica is along the bottom of the image, below and to the right of the east coast of South America), the Oronteus Finaeus World Map of 1532, and the Hadji Ahmed World Map of 1559. A projection of the Oronteus Finaeus map (see here) compared to the outline on today's maps clearly shows the deep fjords of the medieval map versus the relatively smooth coastline depicted on modern maps based on the ice cap which reaches to the ocean and covers up all the folds of the actual coastline.

In the online version of his book on the hydroplate theory, Dr. Brown discusses these medieval maps and their implications for the timeline of the Antarctic ice cap:
These medieval maps, copied 2–3 centuries before 1819 (when textbooks say Antarctica was discovered) were probably based on much earlier source maps. These and other medieval maps also suggest much lower sea levels before the Ice Age. (The hydroplate theory explains why lowered sea levels were followed by the Ice Age.) The maps provide additional information on Antarctica’s mountain ranges, plateaus, bays, coastal islands, and former rivers—under about a mile of ice today. Obviously, the Antarctic ice cap grew rapidly and recently as humans were exploring the earth. The ice cap did not grow, as taught for the last century, over millions of years or before man allegedly evolved.
The ongoing discoveries in the Antarctic, including the new details revealed by ice-penetrating radar in the Aurora Subglacial Basin and published earlier this year in Nature, appear to provide additional supporting evidence for the accuracy of Dr. Brown's theory and its predictions.