Ledoyom ( rus, ледоём, p=lʲɪdɐˈjom) is a term proposed by the Russian geologist V.P. Nekhoroshev for

intermontane Intermontane is a physiographic adjective formed from the prefix " inter-" (''signifying among, between, amid, during, within, mutual, reciprocal'') and the adjective "montane" (inhabiting, or growing in mountainous regions, especially cool, moi ...

depressions which might get completely filled by

glaciers A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as ...

from the surrounding mountains at the maxima of

glaciation A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betw ...

Information

In the 1930s the Russian geologist V.P. Nekhoroshev marked out intermontane depressions in the Altai which might get completely filled by glaciers from the surrounding mountains at the maxima of glaciation. He called such depressions "ledoyoms". The Russian term “''Ledoyom'' (ледоём)” means “body of ice” by analogy with a “body of water” ("vodoyom"). Ledoyoms produced large valley

glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its Ablation#Glaciology, ablation over many years, often Century, centuries. It acquires dis ...

s within outlet runoff valleys from the depressions at culmination stages of their development. Diagnostic marks of the so-called classical ledoyoms are

moraine A moraine is any accumulation of unconsolidated debris (regolith and rock), sometimes referred to as glacial till, that occurs in both currently and formerly glaciated regions, and that has been previously carried along by a glacier or ice shee ...

esker An esker, eskar, eschar, or os, sometimes called an ''asar'', ''osar'', or ''serpent kame'', is a long, winding ridge of stratified sand and gravel, examples of which occur in glaciated and formerly glaciated regions of Europe and North Amer ...

s and

kame A kame, or ''knob'', is a glacial landform, an irregularly shaped hill or mound composed of sand, gravel and till that accumulates in a depression on a retreating glacier, and is then deposited on the land surface with further melting of the g ...

s on the bottoms of the corresponding depressions. In the 80s and 90s the development of the idea by Russian geologist Alexei Rudoy (russian: Алексей Рудой) of glacier-dammed lakes which used to fill most of the inter-montane basins of the mountain belt of

Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of ...

, the depressions of Teletskoye and

Baikal Lake Baikal (, russian: Oзеро Байкал, Ozero Baykal ); mn, Байгал нуур, Baigal nuur) is a rift lake in Russia. It is situated in southern Siberia, between the federal subjects of Irkutsk Oblast to the northwest and the Repub ...

lakes including, took place. It also became clear that many depressions, even very large ones, had been already occupied by dammed water basins by the time when the glaciers of the mountain frame moved forward into them. Thus, mountain glaciers turned into original “ shelf” glaciers and armored completely the surface of the glacier-dammed lake joining together floating on the surface. That is the way the so-called “captured lakes” came to exist. At maximum lowering of the

snow-line The climatic snow line is the boundary between a snow-covered and snow-free surface. The actual snow line may adjust seasonally, and be either significantly higher in elevation, or lower. The permanent snow line is the level above which snow wil ...

(in the Altai and the Sayan its depression gave about 1200 m in late

pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

) some of the lakes (

Chuya The Chuya (russian: Чуя; alt, Чуй, ''Çuy'') is a river in the Altai Republic in Russia, a right tributary of the Katun ( Ob's basin). The Chuya is long, and its drainage basin covers . The river freezes in October or early November and ...

, Kuray, Uymon and others) began functioning in an under-ice regime because they never got free from ice for thousands of years. Such lakes turned into ice bodies of the “

aufeis Aufeis, ( ), (German for "ice on top") is a sheet-like mass of layered ice that forms from successive flows of ground or river water during freezing temperatures. This form of ice is also called overflow, icings, or the Russian term, naled. The t ...

” type. They consisted of a thick lens of lake water, which was covered by lake

ice Ice is water frozen into a solid state, typically forming at or below temperatures of 0 degrees Celsius or Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaq ...

and

ice, and by

snow Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water throughout ...

firn __NOTOC__ Firn (; from Swiss German "last year's", cognate with ''before'') is partially compacted névé, a type of snow that has been left over from past seasons and has been recrystallized into a substance denser than névé. It is ice that ...

sequence, too. “Aufeis” ledoyoms became independent centers of

with subradial ice outlets. Possible analogies of such an evolution mechanism and pre-glacial lakes are thick water lenses under a 3–4 kilometer-thick unit of the glacier cover at the sites of Dome B and

Dome Charlie Dome C, also known as Dome Circe, Dome Charlie or Dome Concordia, located at Antarctica at an elevation of above sea level, is one of several summits or "domes" of the Antarctic Ice Sheet. Dome C is located on the Antarctic Plateau, inland from ...

and the

Vostok Station Vostok Station (russian: :ru:Восток (антарктическая станция), ста́нция Восто́к, translit=stántsiya Vostók, , meaning "Station East") is a Russian Research stations in Antarctica, research station in ...

in Eastern

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest contine ...

. Thus, depending on the intermontane depression topography, the values, of the snow-line depression and of the glaciation energy, the interrelation of the glaciers and the ice-dammed lakes in the

mountains A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher th ...

south South is one of the cardinal directions or Points of the compass, compass points. The direction is the opposite of north and is perpendicular to both east and west. Etymology The word ''south'' comes from Old English ''sūþ'', from earlier Pro ...

of Western

could develop according to the following scenarios: (1) A ledoyom only (no ice-dammed lake). In such cases some glacial and water-glacial relief forms and sediments would remain in the basins; (2) A water body and a ledoyom together (the stage of “catch lakes”). Certain forms of “dead ice” may remain in the basins, as well as intraglacial water-ice forms – eskers and kames which were projected onto the bottom lake deposits when the “shelf” ice descended; (3) “Aufeis” ledoyoms; (4) An ice-dammed lake only. Under different extensions of the

at different time periods, one and the same basin underwent different sequences of the lake-glacier events.''Рудой А. Н.'' Четвертичные ледоемы гор Южной Сибири // Материалы гляциологических исследований, 2001. — Вып. 90. — С. 40 — 49.

References

Keenan Lee. The AltaiFlood.

Ledoyom. Museum of Learning Explore a Virtual Museum of Knowledge

Alexei Rudoy. Ледоёмы (ice body): обзор

Alexei Rudoy. Giant current ripples: A Review (Гигантская рябь течения: обзор новейших данных). 29. 12. 2010.

Alexei Rudoy. Прошлогодний снег. – Climate, ice, water, landscapes
{{Webarchive, url=https://web.archive.org/web/20110506040501/http://ice.tsu.ru/index.php?option=com_content&view=category&layout=blog&id=8&Itemid=99 , date=2011-05-06 Geomorphology Glaciology