Caucasus MountainsThe Caucasus Mountains are a mountain range at the intersection of Asia and Europe. Stretching between the Black Sea and the Caspian Sea, they are surrounded by the Caucasus region and are home to Mount Elbrus, the highest peak in Europe at above sea level. The Caucasus Mountains include the Greater Caucasus in the north and Lesser Caucasus in the south. The Greater Caucasus runs west-northwest to east-southeast, from the Western Caucasus on the northeastern shore of the Black Sea to Baku on the Caspian Sea.
Lena (river)The Lena (Ле́на, ˈljɛnə; Елюенэ, Eljune; Өлүөнэ, Ölüöne; Зүлхэ, Zülkhe; Зүлгэ, Zülge) is a river (En: Helen) in the Russian Far East, and is the easternmost of the three great Siberian rivers that flow into the Arctic Ocean (the other two being the Ob and the Yenisey). The Lena is the eleventh-longest river in the world, and the longest river entirely within Russia, with a length of and a drainage basin of . Permafrost underlies most of the catchment, 77% of which is continuous.
HydrosphereThe hydrosphere () is the combined mass of water found on, under, and above the surface of a planet, minor planet, or natural satellite. Although Earth's hydrosphere has been around for about 4 billion years, it continues to change in shape. This is caused by seafloor spreading and continental drift, which rearranges the land and ocean. It has been estimated that there are 1.386 billion cubic kilometres (333 million cubic miles) of water on Earth.
PalsaPalsas are peat mounds with a permanently frozen peat and mineral soil core. They are a typical phenomenon in the polar and subpolar zone of discontinuous permafrost. One of their characteristics is having steep slopes that rises above the mire surface. This leads to the accumulation of large amounts of snow around them. The summits of the palsas are free of snow even in winter, because the wind carries the snow and deposits on the slopes and elsewhere on the flat mire surface.
Climate change feedbackClimate change feedbacks are effects of global warming that amplify or diminish the effect of forces that initially cause the warming. Positive feedbacks enhance global warming while negative feedbacks weaken it. Feedbacks are important in the understanding of climate change because they play an important part in determining the sensitivity of the climate to warming forces. Climate forcings and feedbacks together determine how much and how fast the climate changes.
Rock glacierRock glaciers are distinctive geomorphological landforms, consisting either of angular rock debris frozen in interstitial ice, former "true" glaciers overlain by a layer of talus, or something in-between. Rock glaciers are normally found at high latitudes and/or elevations, and may extend outward and downslope from talus cones, glaciers or terminal moraines of glaciers. There are two types of rock glaciers: periglacial glaciers (or talus-derived glaciers), and glacial rock glaciers, such as the Timpanogos Glacier in Utah, which are often found where glaciers once existed.
Frost lineThe frost line—also known as frost depth or freezing depth—is most commonly the depth to which the groundwater in soil is expected to freeze. The frost depth depends on the climatic conditions of an area, the heat transfer properties of the soil and adjacent materials, and on nearby heat sources. For example, snow cover and asphalt insulate the ground and homes can heat the ground (see also heat island). The line varies by latitude, it is deeper closer to the poles.
Franz Josef LandFranz Josef Land (Zemlya Frantsa-Iosifa; Fridtjof Nansen Land) is a Russian archipelago in the Arctic Ocean. It is inhabited only by military personnel. It constitutes the northernmost part of Arkhangelsk Oblast and consists of 192 islands, which cover an area of , stretching from east to west and from north to south. The islands are categorized in three groups (western, central, and eastern) separated by the British Channel and the Austrian Strait. The central group is further divided into a northern and southern section by the Markham Sound.
Polar regions of EarthThe polar regions, also called the frigid zones or polar zones, of Earth are Earth's polar ice caps, the regions of the planet that surround its geographical poles (the North and South Poles), lying within the polar circles. These high latitudes are dominated by floating sea ice covering much of the Arctic Ocean in the north, and by the Antarctic ice sheet on the continent of Antarctica and the Southern Ocean in the south.
CryoturbationIn gelisols (permafrost soils), cryoturbation (frost churning) refers to the mixing of materials from various horizons of the soil down to the bedrock due to freezing and thawing. Cryoturbation occurs to varying degrees in most gelisols. The cause of cryoturbation lies in the way in which the repeated freezing of the soil during autumn causes the formation of ice wedges at the most easily erodible parts of the parent rock. If the parent rock is hard, this can cause quite deep erosion of the rock over many years.
