What Caused The Ice Ages?

Here is one of those questions of the ages. On a roughly regular basis, the earth grows colder until it enters a so-called "ice age" maybe 8,000 years in duration.Then, it grows warmer until the ice age ends and a warm period of about 15,000 years follows. After this, the cycle repeats over and over again. These ice ages began somewhat suddenly in the earth's history.

The question is: why? There are a number of theories that you may read about in the article about the ice ages on www.wikipedia.org if you wish. Many believe that it is factors outside the earth that are responsible for the ice ages such as variations in the output of the sun or perturbations in the orbit of the earth around the sun.

I just cannot believe this. I have long been certain that there must be some cyclic process on earth that bears the primary responsibility, for one thing no signs of any alternating cold periods have been found on other planets. I have written about this previously, but today I would like to introduce a complete theory of the ice ages.

The ice ages, and the massive glaciers that it produces, does a lot to shape the landscape of much of the earth's surface. During the warm periods about 10% of the earth is covered by ice, but this increases to about 30% during the ice ages.

Glaciers begin to form when it gets cold enough so that the snow of one winter has not completely melted by the time the following winter begins. Snow begins to pile up year after year, decade after decade and, century after century. The snow in the lower levels is compressed into ice by the weight of the snow above it. The eventual result is a massive sheet of ice stretching across the landscape and two or three kilometers in height. When an object is large enough, it is affected by the rotation of the earth and the glaciers are pulled toward the equator and somewhat to the east by the earth's rotation.

The white surface of the snow and ice reflects a lot more solar radiation back to space than the darker ground beneath. Thus, we get a cooling spiral started which forms still more ice. This ice does not flow through the watershed back to the sea, as it would if it were rainfall. This causes a drop in sea level of maybe a couple of hundred meters, and leaves a lot of land connections that were not there during the warm periods such as the land bridge across the Bering Strait and a land connection from mainland Asia to Japan.

It is fairly easy to explain why the ice ages began. We know that the carbon dioxide in the atmosphere acts as a greenhouse gas, and causes the earth to warm. Basically, the earth absorbs radiation from the sun each day and grows warm. The earth re-radiates this radiation back into space, but does so at different wavelengths than the incoming radiation. A greenhouse gas in the atmosphere, like carbon dioxide, causes the earth to get warmer by allowing the incoming wavelengths through but blocking the outgoing wavelengths so that heat is trapped.

Much of the structure of plants is carbon. Leaves use energy from the sun to split molecules of carbon dioxide, releasing the oxygen back into the air and using the carbon to build the structure of the plant. Dead plants may become buried or submerged before they can decay. This is how limestone (calcium carbonate), coal and, oil form over long periods of time, and when this happens carbon is removed from the air.

Could it be that the earth was once warmer than it is today because of a higher level of carbon dioxide in the air, but it began to cool when enough carbon became buried as the dead plants which formed coal and oil? This could have reached a point which got the ice ages underway. Of course, we are in the process of reversing this by burning fossil fuels and bringing about global warming.

We have seen how the ice ages began. But that still does not explain why the earth gets colder and than warmer in a recurring cycle. However, I have noticed a simple explanation.

We know that plants pull carbon dioxide out of the air as they grow. The carbon is incorporated into the structures of the plants, while the oxygen that it is separated from is circulated back into the air. When the plant dies and decays, the carbon is oxidized and returns to the air as carbon dioxide.

Now, here is the question to ponder: What about the roots of the plants? The structure of the dead plant that is above ground decays back into the carbon dioxide from which it was formed, but the roots remain under the ground. The roots will also decay, but most of the carbon of which they are composed will be blocked from returning to the air and will remain in the ground.

This is the reason that plowing the soil releases so much carbon dioxide, the carbon from long-decayed roots of dead plants is being released back into the air. My hypothesis is that, when enough carbon is removed from the air as plant roots, the earth cools enough to bring about another ice age.

It is no secret that the most fertile lands on earth are those over which glaciers have moved during the ice ages. The reason is that the nutrients that are vital to plants tend to get lost in the soil over time, and the plowing done by a moving sheet of ice brings the nutrients back up. But if this glacial plowing brings back nutrients to near the surface, think of how much carbon dioxide it must release also. All of the carbon from the decayed roots of countless generations of dead plants would suddenly be released, just as if the soil were being plowed with a giant plow.

The arctic regions are not the only source of glaciers during ice ages. The same effect takes place as vast sheets of ice form by the glacial process in mountainous regions, due to the higher and colder air. We saw this in the posting "Mountains And Glaciers", on this blog.

The next factor that comes into play is earthquakes. Most mountains, unless of volcanic origin, are formed by tectonic collisions that are still, more or less, taking place. Thus, the mountainous regions that host extensive glaciers during the ice ages are especially prone to earthquakes, which do not stop just because it is an ice age.

What happens is that the earthquakes jolt glaciers loose so that they slide down to the lowlands below, and in doing so plow the soil to great depth so that thouands of years of carbon dioxide from decayed plant roots is released into the air. This causes the earth to warm because carbon dioxide is a greenhouse gas, and this ultimately brings about the end of the ice age.

This process brings about a spiral. The plowing of adjacent lowlands by glaciers from mountains, knocked loose by earthquakes during the ice ages, also brings nutrients to the surface. This makes the area fertile so that plants will flourish during the ensuing warm period, and will leave even more carbon in the ground as the roots of the plant after the end of it's life.

Just by looking at a map, it is easy to see the link between earthquakes in mountainous regions and glacial activity in the lowlands below. Here is a map link: www.maps.google.com .

Argentina has a vast continental shelf, which could have easily been formed as the land was carved away by moving glacial ice, that is about as large as the country itself. Argentina happens to be just east of the Andes Mountains, which undergo the extremely powerful earthquakes of a subduction zone such as the 2010 Chile earthquake. Momentum from the earth's rotation would pull the loosened glaciers eastward, across Argentina.

Greece is also vulnerable to earthquakes. The Aegean Islands are on a shallow shelf that has been mostly carved away by glacial activity. Crete appears to be the furthest extent of the shelf. Glaciers from the mountains to the northwest, pulled by the earth's rotation to the south and east after having been shaken loose by earthquakes during the ice ages, carved away most of the landscape and left the islands.

Italy, as well as Greece, is on a tectonic plate that is vulnerable to earthquakes. The Adriatic Sea is actually a shallow glacial raceway, formed where the ground has been carved away by glacial movement toward the south and east through the gap between the mountains of Italy and those of the former Yugoslavia. Glaciers from the mountains all around, especially the Alps, were shaken loose by earthquakes and pulled by the momentum of the earth's rotation to the south and east.

The Persian Gulf region is the site of heavy glacial activity, which plowed the ground to produce what is known as the Fertile Crescent and eroded away what is now the shallow Persian Gulf in much the same way as the Adriatic Sea. The glaciers came from the nearby Zagros Mountains of Iran, which is very vulnerable to earthquakes, and were pulled by the momentum of the earth's rotation to the south and east.

The mountains of south China must have hosted extensive glaciers during the ice ages, and are also very vulnerable to earthquakes. I pointed out the route of the Red River in "Mountains And Glaciers". A wide area was carved away by the glaciers, knocked loose by earthquakes and pulled by the earth's roation to the south and east, leaving Hainan Island intact and leaving Vietnam with a wide and shallow continental shelf.

North China is generally less vulnerable to earthquakes than the south. But it appears logical that earthquakes jolted mountain glacial ice loose during the ice ages to carve the shallow extension of the Yellow Sea known as the Bo Hai, near the cities of Dalian and Tianjin.

In contrast, the Rocky Mountains of North America are not known for earthquake activity and no evidence of such glacial activity is to be seen nearby. Neither is there any sign of large-scale glacial activity around the Adirondack Mountains of New York State or the mountains of New England. The area is very mildly seismic, but no large earthquakes.

The area around the Appalachian Mountains do not display any signs of such glacial activity, except for the pair of Chesapeake and Delaware Bays. But these were formed by glacial movement being focused by the curve in the Appalachians across Pennsylvania, and are nowhere near the scale of the glacial activity described above.

So, there can be no doubt that there is extensive glacial activity that can be seen to have taken place around mountains that would have hosted extensive glaciers during the ice ages and that are vulnerable to earthquakes. Since the most fertile areas in the world are those which have been plowed by glaciers, and since plowing soil is known to release large mounts of carbon dioxide into the air, we can safely assume that plowing by glaciers releases carbon in the soil that has built up during the warm periods between the ice ages, and that this is ultimately what brings the ice age to it's end until the carbon is put back into the soil by the remaining roots of dead plants during the warm period, and this ultimately brings on the next ice age. The plants thrive in this area because the glacial plowing that released the carbon also brought buried nutrients to near the surface.

How else can the recurring cycle of ice ages and warm periods be explained? Isn't this the most logical explanation? Isn't it amazing that without earthquakes there would be a continuous ice age?