Types of permafrost and the effect of its melting

July 5, 2016 by • Permafrost melting, The effect of climate change •

Over the past few decades, the problem of climate changes has been a serious issue discussed and observed by many people.The facts is that they are truly happening and affecting the climate in the whole world, on the scale, we still cannot imagine.

One of the greatest concerns of scientists is the melting of ice in the Arctic and Antarctic regions, which can cause a series of problems for the environment. The scientists who study the melting of ice also observe the changes in permafrost, a frozen layer which lies beneath the surface of the Earth. It consists of soil, sand and gravel which are bound together by ice, and to be classified as permafrost, this layer needs to stay below 0°C for at least two years. Permafrost can be found mostly in and around Arctic and Antarctic region, but also on some mountains, and even beneath the seabed in the Polar Regions.

ArcticMethaneRelease_750_318993Permafrost can significantly differ in thickness. The thinnest permafrost layer is around 3 feet thick, while the thickest layers can go as far as 3,280 feet in depth. Permafrost covers around 8.8 million square miles and it is found mainly in the Northern Hemisphere. This means that it accounts for 24% of exposed land in this part of the Earth. On the other hand, when compared to the water on our planet, it accounts for 0.022% of total water.

It is important to differentiate permafrost from frozen ground. In some parts of the world, the ground can freeze during the coldest days. Such frozen ground can be divided into two groups: seasonally frozen ground, which stays frozen for over 15 days a year, and intermittently frozen ground, which stays frozen for less than 15 days a year. In order for the frozen ground to be classified as permafrost, it must stay frozen for over two years.


Permafrost can also be divided into two groups: continuous and discontinuous. Continuous permafrost extends under all surfaces as a continuous layer of frozen ground, and it can be found in Siberia. Discontinuous permafrost, as the name suggests, covers separate areas with frozen ground. In the areas with thick vegetation

or in the shadow of a mountain, discontinuous permafrost can stay frozen all year round while the parts in the sun can melt for a few weeks or months during summer. This type of permafrost can be found in the southern part of Hudson Bay in Canada.

 

current_state_permafrost_0081 The studies conducted over the 20th century show that permafrost warmed by 6°C over that period. Scientists warn that widespread melting of permafrost may occur by the year 2100, and there is a series of concerns related to this event. When permafrost melts, it releases large quantities of carbon dioxide and methane. This could add to the greenhouse effect by adding the gasses which cause it, which could lead to additional warming of the Earth. At this point, permafrost does not emit a significant amount of methane and carbon dioxide into the atmosphere. However, if the total melting occurs, it may have a serious impact on the Earth’s climate.