Mysteries of glaciation
Thomas R. Henry, a member of Byrd’s expedition of 1946-47, in his book The White Continent writes:
Within the past few million years the continental ice sheet has been much thicker and flowed over the tops of mountains in the rim of the bowl. . . . Perhaps fewer than a million years ago the frozen ocean which now covers the interior of the continent was hundreds of feet deeper than at present.
As a matter of fact, the lower the temperature, the less is the snowfall. Heavy snowfalls occur only in comparatively mild, not excessively cold weather, and heavy snowfalls in the north and south polar regions are a myth. The reports of Scott, Shackleton, Peary and others who have been there agree that there is very little snowfall, in fact practically none, in the interior of Antarctica, Greenland, or on the sea ice in the Arctic Ocean. Even sled tracks of former expeditions have remained visible to subsequent explorers years later. Peary writes that “the ceaseless winds blowing from the interior outward toward the periphery of the Greenland ice cap prevent increase in the height of the ice.” The interior of Antarctica is an ice-covered continent quite beyond the reach of heavy snowfalls resulting from condensation of water vapor formed in warmer zones. Such vapors fall long before they reach the interior of Antarctica or exist as impenetrable, constant fogs in latitudes much farther north. Relative to precipitation in the interior of the continent, Henry writes:
The everlasting wind blowing from the pole is as dry as the winds over the Sahara. . . . This lack of precipitation is the chief factor operating to bring the Antarctic ice age to an end.
He says the ice cap is constantly flowing outward through the mountain gaps. … If this movement should continue for a few more hundred thousand years the ice cap may almost entirely disappear.
Flint says (pp. 49-50) that precipitation at Little America Station at the outer edge of the Ross Shelf is equivalent to only 7/2 inches of rain; and on most parts of Antarctica it is probably less than 5 inches.
Proponents of the refrigeration hypothesis may discount as immaterial the fact that mountain glaciers in Alaska, in Pacific Coast ranges, in Glacier National Park, in the Alps, in Scandinavia, in South America—in fact, all over the globe—are presently shrinking, as they positively are; but when we know that the great continental ice sheet is also steadily diminishing in
Antarctica, the coldest area on Earth, where temperature never rises above freezing, how can anyone possibly continue to believe that a still colder climate would cause glaciers to accumulate and institute another glacial age? It surely is evident that increased precipitation of snow would be necessary to augment Antarctica’s present ice sheet. If this ice blanket is not increasing today in that frigid climate, does it not clearly follow that cold climate did not cause the ice to accumulate in the first place?
It seems strange that learned scientists would so long cling to the hypothesis that colder climate could have been the cause of ice ages. As said previously, the only possible explanation must be that they have failed to envision any other cause.
Doubt in Theory Is Growing
In earlier years of glacial study doubts were expressed only very rarely, and then quite timidly, that perhaps colder climate would disfavor rather than stimulate glaciation. Recendy, more and more scientists are inclining to this latter view. For instance, Dr. Donald H. Menzel of Harvard, in his paper on The Causes of Ice Ages, read in 1952 at a conference sponsored by the Rumford Committee of the American Academy of Arts and Sciences, as quoted in Howard Shapley’s Climatic Change, said:
I have always believed that an ice age is not, of necessity, a cold age. … In fact, as others have noted, an increase of solar radiation, rather than a decrease, may well bring about an ice age, because of the greater evaporation from the oceans produced by the stronger solar radiation. … As I see it, we need both greater precipitation and greater cloudiness—two primary agencies necessary to ice formation.
Dr. Barbara Bell, in her paper Solar Variation, given at the same conference, writes:
Let us now consider what solar variation needs to be postulated to explain best the observed periods of extensive glaciation. The more obvious hypothesis states that the ice ages result from a decrease in the solar radiation, with a consequent lowering of Earth’s temperature. But Sir George Simpson has severely criticised this hypothesis. He points out that the principal consequence of such cooling would be a great decline in the moisture content of the atmosphere, in precipitation and in general vigor of atmospheric circulation.
Dr. Bell goes on to say that due to such reduced precipitation it would be “virtually impossible to build up any appreciable ice sheet on the land.” She adds that no satisfactory answer to Simpson’s criticism has been produced.
Other similar opinions have lately been expressed. Thus it is evident that suspicions are finally developing that the colder-climate hypothesis is not tenable. But instead of aiding in the quest for a solution of glacial mysteries, these growing suspicions can only magnify the problem, unless and until some alternate cause of ice ages is presented to take the place of the doubtful supposition that cold climate was the cause and surface waters the source of the ice. Such an alternate cause will be disclosed in pages to follow.
Did Oceans Supply Moisture?
Considering next the idea that glacial ice came from evaporated surface water, let us try to estimate how much water would have to be evaporated to fill the order. It has been estimated that the ice still remaining on Earth would, if all melted, raise the ocean level by nearly 200 feet. Certainly, the maximum amount of ice contained, say in the Pleistocene Ice Age, was several times greater than the volume still remaining. It seems reasonable to believe that oceans would have had to be lowered at least many hundreds of feet, to produce the indicated quantity of ice in any of the major ice ages.