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Ice Cores (Sidebar 4)
Ice Age Evidence
While the evidence of enormous glaciers existing in the past is prevelent, scientists disagree on the timing, number of ice ages and the mechanism of ice ages. Young-age scientists will place the single "Ice Age" at approximately 1000 – 3000 years B.C., while long-age modelists estimate the most recent "Ice Age" at 160,000 years ago and even older "Ice Ages" millions of years ago.
Evidence of at least one ice age can be found all over the earth. Evidence of glaciers covering North America, Europe and Asia is abundant. The glacial debris contains deposits of rocks of all sizes chaotically mixed with finer-grained material. Large areas of North Dakota, Montana, and Saskatchewan are covered with parallel grooves with intervening ridges that are best seen from the air. Hard rock surfaces are polished, scratched and grooved indicating the passage of a deformable mass past these surfaces. Approximately 3000 years ago agriculture was common in the Middle East and northern Africa which are covered by deserts today. NASA satellite images reveal vast river channels and tributaries buried beneath the sand of the Sahara. This is consistent with the greater rainfall expected just south of a glacial ice sheet in Europe and western Asia.
Ice Age Beginnings
How does an Ice Age begin? Scientists have debated this for years. It was once thought that colder winters are required, but the winters at present are cold enough to maintain an Ice Age. "In fact, winters are now too cold in many northern localities. Consider Siberia: The temperatures there average far below zero Fahrenheit in winter, but no glaciers exist."[1] Instead what is needed is a colder summer. Snow must survive through the winter without melting to accumulate vast ice sheets. Greater precipitation in the form of snow is also needed to create an Ice Age. If the snowfall is light it would melt during the summer. The main requirements for an Ice Age are cooler summers and increased snowfall. Although the requirements for an Ice Age are known, the mechanism for starting an Ice Age is difficult to postulate. One of the difficulties in initiating an Ice Age is that lower temperatures are often accompanied by lower precipitation. For example, Keewatin, northwest of the Hudson Bay in northern Canada thought to be one of the two centers for ice sheet growth in the last "Ice Age", has winters that are currently too cold for significant snowfall. It is a polar desert with an average precipitation of 8 inches, most of which falls during the summer rains."Yet the mechanism and quantitative adequacy of the effect [discussing the astronomical theory] pose major difficulties, and the nature of the climatic changes responsible for the present ice sheets and for the growth and decay of the Pleistocene glaciers are still problematical. The moisture sources and mechanisms permitting the growth of the Northern Hemisphere ice sheets also remain to be established. . .][2]These requirements are very difficult to meet under a uniformitarian theory. Could the requirements of a cooler summer and heavier snowfall be more readily explained by a worldwide Flood? Ice Age Following a Worldwide Flood
Many significant geological events occurred during the Flood. "Mountains rose up and valleys were carved out by receding flood waters; volcanoes spewed lava and dust over vast areas; forests were buried, and earthquakes and tidal waves swept the earth. Even the continents may have been broken apart during or shortly following the Flood." [3] After the flood waters receded, the geological processes would have slowly decreased for many years, much like aftershocks following an earthquake. Volcanic eruptions would have continued for many years after the initial Flood event. Significant volcanic eruptions would be needed to change the weather for several summers in a row and trigger the start of an Ice Age. One eruption of the Tambora volcano in 1815 is believed to be responsible for unusually cold weather in New England and Europe during the summer of 1816. Heavy snow fell in June and frost caused crop failures in July and August. While not every large eruption is followed by a corresponding climate change, there is evidence that even a single volcano can have effects that last for a several years. "Volcanic dust and aerosols act like an 'inverse greenhouse,' by reflecting solar radiation back to space, while still allowing infrared radiation to escape the earth's surface" [4] The dust emitted from an eruption settles quickly and may only effect the weather for a few months. The aerosols such as sulfur and halogen compounds stay airborne much longer and contribute more to atmospheric cooling. There are high concentrations of calcium, magnesium, and silicon in the lowest layers of ice cores which may be traced to heavy volcanic activity at the beginning of the Ice Age. Summer and autumn temperatures are the most influenced by volcanic eruptions. [5] The warm oceans following the Flood would not have been significantly cooled by the volcanic dust and aerosols, but the land would have cooled substantially. The ocean temperatures would have been drastically changed during the Flood. The average temperature may have been raised tens of degrees due to the amount of energy released during this catastrophic event. The oceans would have been uniformly warmer from pole to pole and at all depths due to the incredible mixing during the worldwide Flood. The combination of warm ocean waters and cold continents probably resulted in intense storms along the coastlines. The heaviest storms would have occurred at the poles where the temperature differences were the greatest. The atmosphere over the poles would have the maximum radiational cooling while the ocean water was possibly as warm as 30o C. The evaporation rate would have been very high with condensation and freezing aloft. The intense convection would then organize itself into a hurricane by drawing in warm surface air and humidity which is deflected by Coriolis forces into spiral rain bands. The storm would have begun over the pole the size of a typical hurricane but positive feedback would have expanded it to cover a major portion of the hemisphere. Initially, the precipitation would fall as rain, but as the oceans began to cool, the precipitation turned to snow around the poles. Oard's model suggests the hurricane probably developed about 100 years after the Flood with the Ice Age beginning approximately 500 years after the Flood. The Growth of an Ice Age
Several aspects of a post-Flood climate would reinforce an Ice Age development through positive feedback. The same conditions that would start an Ice Age would also tend to cause an Ice Age to grow in scope and magnitude. The post-Flood Ice Age model indicates a rapid development such as a "snowblitz." A snowblitz covers a vast area with snow in a single winter. Then the following summer, the snow fails to melt and instead radiates the suns heat away from the earth keeping the summer air temperature cool. The cold comes almost immediately and the ice sheet builds higher year after year without reducing during the summer. This implies that an Ice Age could start suddenly instead of slowly growing out from local mountainous areas. Snow accumulated on the land masses first and would have contributed to the atmospheric cooling. Snow cover cools the atmosphere by increasing the reflectivity of solar radiation. Fresh snow reflects about 80% of the solar radiation, five times the amount of reflectivity of bare ground. Snow is also a good insulator, shielding the atmosphere from the warmer ground. "Thus, if snow and ice covered the whole surface of the Earth even for a short period of time, its mean temperature (equal now to 15oC) would be reduced by approximately 100oC." [6] Barren land can also act as a reinforcement for snow cover cooling, because the flat surface reflects more solar radiation than a forest covered in snow. The post-Flood landscape would have been nearly devoid of trees and could explain the lack of vegetation remnants in glacial drift. The uniformitarian theory explains this lack of vegetation by postulating that the trees and vegetation were killed by the temperature drop just prior to the glacier advance from the north. However, if the climate was cold enough to kill all vegetation, it would have been too dry to form an Ice Age.Another mechanism for cooling the atmosphere is an increase in cloud cover. Due to the high evaporation rates off of the warm ocean waters, there would have been more cloudiness and precipitation after the Flood. Increased cloudiness could lead to cooler summers and less snowmelt allowing ice to accumulate in successive years.Large amounts of precipitation on the ocean surfaces may have been great enough to create a layer of fresh water that would freeze, fresh water having a higher freezing point than saltwater. This ice layer would have stopped evaporation at the poles and would have reflected solar radiation causing the water below to cool further. The ice sheet would have continued to grow outward from the most intense precipitation at the center of the hurricane. The ice sheets at the poles would have developed differently due to the land distribution differences of the two poles, with the north pole ice sheet developing the slowest. As the oceans cooled and more of the oceanic evaporation sites became covered in ice, the precipitation zones would also have moved further equatorward. Eventually, the oceans would have cooled enough to slow evaporation allowing the summer melts to exceed the winter snowfall leading to a reduction in ice sheet growth. The driving force in the beginning and growth of the Ice Age was the warm oceans following the Flood. According to Oard's model "when the average ocean temperature cooled to 10oC, less oceanic evaporation occurred, fewer clouds were present at higher latitudes, more radiation penetrated to the surface, and most ice sheets began to melt." [7]As the Ice Age ended, the climate became harsher with colder and drier winters. Many large animals (woolly mammoths and rhinoceroses, saber-toothed tigers, giant short-faced bears, ground sloths, etc.) would have starved to death before migrating to suitable environments. Man may have hunted the remaining animals to extinction since they were the only food source. Arrowheads in the remains of woolly mammoths and cave paintings attest to their being a significant food source for man during this period. References
1. Oard, Michael J., An Ice Age Caused By The Genesis Flood, San Diego, CA, Institute for Creation Research, 1990. p. 2. Return to Text
2. Washburn, A.L., "Focus on Polar Research." Science, 209, 1980. p. 648. Return to Text
3. Vardiman, Larry, Ice Cores and the Age of the Earth,San Diego, CA, Institute for Creation Research, 1996. p. 51. Return to Text
4. Oard, p. 34. Return to Text
5. Bradley, R.S., "The Explosive Volcanic Eruption Signal in Northern Hemisphere Continental Temperature Records."Climatic Change, 12, 1988. pp. 221-243. Return to Text
6. Budyko, M.I., "The Heat Balance of the Earth." Climatic Change, J. Gibbin, ed., 1978. London, Cambridge University Press, p. 95. Return to Text
7. Oard, p. 109. Return to Text
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