Permafrost

(based on the ground temperature record at 10 m depth). Nevertheless, the degradation of the
lithalsa was accelerated in recent years through subsurface warming by heat carrying
groundwater flow across the surrounding unfrozen terrain. Indeed, the collapsing half of the
lithalsa is on the upstream side of the regional slope and surface water flow, a pattern that is
apparent also in other degrading palsas and lithalsas in the same wetland.
A numerical model simulating the current thermal degradation of this lithalsa will be
presented with an estimate on the relative amounts of heat carried into the lithalsa by heat
conduction and, eventually, heat advection. It will be argued that warming of the permafrost
core by heat carrying groundwater might well be the dominant process responsible for
degradation of shallow permafrost layers.
Key words: Lithalsa, permafrost degradation, numerical model
126
Negative Consequences of Permafrost Degradation
Grebenets V., Kraev G. Nagornov D.
(Lomonosov Moscow State University, Geographical faculty, Department of Cryolithology and Glaciology)
Abstract: Permafrost occupies about a fifth part of Earth’s surface. Modern observations assess
permafrost condition as unstable due to the global climate warming and human impact. A result
of climate change in fact influences the cryosphere elements: permafrost, glaciers, marine ice.
The influence is taken exaggerated or understated very often as positive and negative parts of it
are discussed. The oldest permafrost is dated 3 million years. Climate has been changing
multiple times until our days. The presence of humanity with the economical demands on the
environment corrects the natural processes. At first human just explored the surrounding
environment extensively in agricultural matters like natives do so today and the centuries before.
As society develop the more areas become used in any purposes. Human impact on this areas
exists anyway, was it a survey information collection or mining or factory work. An observation
of cryosphere response to a clear climate change nowadays is possible only on always
unsuitable for humanity localized areas such as high-mountainous ones. Mountain permafrost
behavior is very complicated depending on multiple factors, basically climatic and geographical
ones. Though the most convenient and more observed cryospheric element for clear climate
change is glacier response.
The amount of urbanized in various extent sites in cryolithozone growing for centuries,
reached maximum during industrialization era and stabilized last decades. Permafrost
investigations at number of the sites are held. It is difficult to separate local microclimatic
changes from urbanized center work energy and mass incomes into atmosphere at any of these
sites. However the biosphere separates lithosphere from atmosphere. That means any changes
of landscape lead to changes in permafrost conditions with the impact of climatic change on or
without it.
Self-restoration of cryolithozone landscapes leads to not identical environment. So on the
route of climate influence on permafrost the landscape stays whether it anthropogenic modified
or not. Results are different. Permafrost condition change on sites of anthropogenic landscape