Климат, лед, вода, ландшафты

Climate, ice, water, landscapes

Рудой Алексей Николаевич

Палеогляциология, палеогеография плейстоцена. "Glacier-dammed lakes..." Alexei N. Rudoy

Fire_LogoЭта статья совсем не новая, хотя актуальности не утеряла. На неё многие ссылаются, однако, если на западе её легко можно почитать, то те, кто ссылается на эту работу в России, вряд ли её видели (за исключением тех моих коллег, которым я презентовал оттиски статьи лично). А потому, эти вот ссылки как раз могут и относиться к "дежурным", к "ссылкам на ссылки". Поэтому я счёл уместным поместить часть текста и гиперссылку на оригинал.

Glacier-dammed lakes and geological work of glacial superfloods in the Late Pleistocene, Southern Siberia, Altai Mountains

© Alexei N. Rudoy

Laboratory of Pleistocene Geology and Palaeogeography, Tomsk State Pedagogical University, Komsomolsky Pr.75, 634041 Tomsk, Siberia, Russia

Abstract
 

Quaternary glacier-dammed lakes of Southern Siberia produced cataclysmic superfloods-floodstreams at the initial and final glacial stages, when the ice dams were unstable. Consequently, the initial surface was greatly and geologically instantly transformed. Morphologic associations of mountainous scablands developed, similar to the diluvial complexes ofthe Channeled Scabland in North America: giant diluvial ramparts and terraces-bars, diluvial berms and giant current ripple relief. Diluvial-erosional and evorsional forms, including spillways, outburst and oversplash gorges, and ‘‘dry waterfalls’’ are also present. The discharges of the glacial superfloods, which have been calculated by independent methods, were hundreds ofcubic meters per second at the locations where the giant current ripple marks were formed, up to millions of cubic meters per second within the gorges. Maximum discharges of 18 ×106m3/s were characteristic of the diluvial floods in the runoff channel from the Chuya–Kuray system of the glacierdammed lakes below the mouth ofthe Kuray depression as far as the settlement of Chibit. The power ofthose floods reached 106W/m2. These values exceed the hydraulic parameters of the jokulhlaups from Late Quaternary Lake Missoula in North America, the floods of which previously were considered the most powerful freshwater streams in Earth history. The last phenomenal glacial superflood with discharges in excess of 1×106m3/s occurred in the Chuya and Katun valleys no later than 13 000 years ago. Afterwards, the glacier-dammed lakes degraded simultaneously with the degradation of the glaciers. The glacier-dammed lakes ofthe intermontane basins in Southern Siberia disappeared completely at some time after 5000 years ago. Calculations of the hydraulics and the estimates ofthe geological activity of the Quaternary jokulhlaups mean that the diluvial processes of relief formation can now be viewed as the most powerful exogenous process. 

© 2001 Published by Elsevier Science Ltd.

JavaScript is disabled!
To display this content, you need a JavaScript capable browser.

1. Introduction_20110503_1318694566

 All ofthe mountains from Eastern Kazakhstan (Tien Shan, Kazakh Altai) to the mountains in the Baikal region belong to the mountains of Southern Siberia, which also includes those of Altai and Tuva. This grand mountainous chain forms a part of the Russian State boundary in the south. The Altai is located near the centre of Asia and is the highest of all mountain ranges in Siberia (some ofthe maximum measured elevations are over 4000 m). The Altai Mountains consist of vast intermontane basins, which were occupied by near-glacial lakes in the Pleistocene, and of high mountain ranges that carry the grandest of modern Siberian glaciers. Numerous climatic zones, which are also peculiar to a certain extent to the neighbouring mountainous countries, are present. The nival-glacial zone changes downwards into the taiga and tundra, into the steppes and the deserts of high-mountain basins, which in turn are adjacent to the mixed woods zone and the zone of South-Siberian steppes. That is why, from the viewpoint of physical geography, the Altai may be considered representative of the whole huge mountainous region of Southern Siberia. From the palaeogeographical and geomorphologic aspects, the Altai is typical of the whole of Central Asia.
 

It is in the Altai that a number of great scientific discoveries have been made during the last decades, which are important for Russian and world-wide Geomorphology, Palaeoglaciology and Quaternary Geology in the 20th century. The chief ones are:
 

(1) Discovery and identification of geological-geomorphological traces of giant Late-Quaternary glacier-dammed  lakes whose regular outbursts resulted in generation of glacial superfloods. Those floods left behind exotic relief forms and deposits (in the first place, giant current ripple marks and diluvial swells and terraces-‘‘bars’’according to Bretz, 1923), similar to the diluvial morpholithologic associations of the Channeled Scabland in North America; and

(2) Discovery of the geological phenomenon of Quaternary Ledoyoms-huge amounts of ice in the intermontane basins. Those ice bodies have a very complicated paragenetic relationship with glacier-dammed lakes (Rudoy, 1991, 1998). The present article deals with the problem of geological and geomorphological effects of the Quaternary jokulhlaups, and that of palaeohydrology and hydraulics of the glacier-dammed lakes and glacial superfloods.

Also see: 

 Baker V.R., Benito G., Rudoy A.N. Paleohydrology of late Pleistocene Superflooding, Altay Mountains, Siberia // Science, 1993. — Vol. 259. — Р. 348—352.

 Rudoy A.N., Baker V.R. Sedimentary Effects of cataclysmic late Pleistocene glacial Flooding, Altai Mountains, Siberia // Sedimentary Geology, 1993. — Vol. 85. — No. 1—4. — Р. 53-62.

Quaternary International 87 (2002) 119–140 _-__QI.pdf


27.05.2011 13:20 35877
 
Прощай мой дом

JavaScript is disabled!
To display this content, you need a JavaScript capable browser.

О проекте

Всё об удивительном и загадочном мире льда и ледников, ландшафтов и людей и их жизни. Всё о планете Земля и о других планетах.

Интересы: снег, вода, горы, лед, катастрофы, все, климат, рельеф, ледники, приледниковые озёра, геоморфология, гляциология, новые теории и проекты в гляциологии, геологии и геоморфологии, а также качественная музыка и всё интересное и в науке, и в экспедициях, что сочтут для себя важным участники проекта, в природе и в жизни.. ....в общем всё.


Наши новости
Текущая информация для студентов
Ключевые слова
Авторизация



logotipЧитателям, слушателям и просто прохожим: сайт и все материалы, опубликованные на нём -  интеллектуальная собственность владельца сайта, и/или авторов соответствующих материалов. Ссылки на сайт, а также ссылки на авторов публикаций,

trudovaslava.info

(и фотографий, разумеется, тоже) обязательны. Соответствующие законы РФ и других стран известны, лицензии - на месте. Воруют, конечно, и не взирая на копирайты, но мы создали сайт для порядочных людей. Не хочется об этом напоминать, но факт любой недобросовестной ссылки-цитирования или пересказа, во- первых, будет предан широчайшей огласке через сеть всеми популярными научными каналами. А далее, возможно, последует и во-вторых..... Спасибо.

Контакты: ran@mail.tomsknet.ru