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Institute of Geology, Earthquake Engineering and Seismology Academy of Sciences of the Republic of Tajikistan Institute of Geology, Earthquake Engineering.

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Presentation on theme: "Institute of Geology, Earthquake Engineering and Seismology Academy of Sciences of the Republic of Tajikistan Institute of Geology, Earthquake Engineering."— Presentation transcript:

1 Institute of Geology, Earthquake Engineering and Seismology Academy of Sciences of the Republic of Tajikistan Institute of Geology, Earthquake Engineering and Seismology Academy of Sciences of the Republic of Tajikistan Prof. Dr. Farshed H. Karimov Dynamics of Large Mountain-Valley Glaciers’ Flow in Tajikistan Berlin December 2014

2 rural Tajikistan: Square ≈ km 2 Population ≥ 7 mln. Mountains - 93% (Pamir, Tan-Shan…) Waters - glaciers, lakes, rivers, reservoirs, underground Climate - sharply continental 27.2 % urban rural

3 Glaciers in Tajikistan – the facts [1,2] Glaciers cover 6% of the Tajikistan territory. Glaciers cover 6% of the Tajikistan territory. Glaciers are the main source feeding the rivers in Tajikistan, composing about 60% of the Middle Asia water resources. Glaciers are the main source feeding the rivers in Tajikistan, composing about 60% of the Middle Asia water resources. Climate global changes made 20 km 3 shortage of waters during the XX century (of 600 km 3 ). Climate global changes made 20 km 3 shortage of waters during the XX century (of 600 km 3 ). For the last 50 years about 30% of glaciers’ square shortage. For the last 50 years about 30% of glaciers’ square shortage. More than 50 glaciers disappeared More than 50 glaciers disappeared Main causes of global climate changes: Industrial and anthropogenic carbon emission Industrial and anthropogenic carbon emission Secular geological cycles Secular geological cycles Solar activity changes Solar activity changes

4 Glaciers and Disasters - > 70 kinds [3]

5 Nurek Power Plant 300 m dam. Water reservoir 10 km 3 volume. Main supply source [1].

6 Sarez Lake, Pamir, Tajikistan. Earthquake triggered river dam [4]

7 Sarez Lake - Google Images

8 The sequences of sils (mudflows), floods, glacial dams’ breaching [5]

9 Yak in Pamir is in the Red Book of Natural Heritage [6]

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14 httpapparat.ccworldshange-earth Aral Lake: The Past & Present Aral Lake: The Past & Present [7]

15 Three types of glaciers’ regarding the overall motion|rest 1.Fixed (small siting on non steep slopes) 2.Moving down on slope with small speed variations (Fedchenko etc.) 3.Surging - pulsing (Khirs – Medvejii – Bear, Garmo, Didal etc.) The Questions: Why glaciers can be fixed? Why glaciers can move (more or less) steadily? Why glaciers can surge? The Questions: Why glaciers can be fixed? Why glaciers can move (more or less) steadily? Why glaciers can surge? Understanding the glaciers

16 Fedchenko’s Glacier, Pamir – A Mountain Valley Glacier [1]

17 Fedchenko’s Glacier - The facts [1,2,8-13]. Fedchenko’s glacier is a mountain-valley glacier, one of the biggest in the Central Asia [1]: Location in Pamirs, Tajikistan Square km 2, Volume km 3, Thickness - up to 1 кm, Average thickness m [1], Ice density average kg/m 3, Mean inclination (4,5 km height per 70 km). Mean flow speed - 0,7 m per day Mead cover ‘s speed - 0,9 m per days, outer thin one - 0,27 m per day [1] In ablation zone - «warm ice» and water accumulation [8] Ice - durability limit (slow quazy static pressure) - 4,5-5,0 МPа (45-50 ton/m 2 ) Ice creep limit % from the durability pressure limit - 2,5-3,0 МPа (see in [8]) Glacier ice density кg/m 3 Viscosity coefficient – Pa·s

18 Glacier – How it does rest, how it does move? «Ice movement at depth was long the subject of debate. Extrusion flow – the hypothesis that glaciers flow more rapidly at depth than at the surface – had its proponents, even in the 1930s. In the early 1900s, Blümcke and Hess used a thermal drill in a glacier in the Tyrol and attained bedrock in eleven holes, one of them more than 200m deep. Rods left in the holes gradually tilted downhill, suggesting that ice moves more rapidly at the surface than at depth.» Cuffey K.M., Patterson W.S.B. Physics of glaciers. Elsevier, 2010, 705 pp. [8]

19 Schematic view of velocity vectors in a mountain glacier [8]

20 Three Physical States of Ice [8-13] Physical conditions Critical ice thicknesses Physical states Compression lesser than plasticity limit 0 Pa< р <2.5 x 10 6 Pa 0 m

21 A Glacier Movement Ideal Scheme α F P F friction z 0 HeHe H

22 Glacier layers cross cut velocity distribution [14] Parabolic dependence of v(z) “Floating” plate z

23 Medvejii|Bear Glacier, Pamirs - A Surging Glacier [1,2] B e a r G l a c I e r A b d u k a h o r River

24 Medvejii - Bear Glacier, Pamirs – A Surging Glacier 15.8 km long up to 150 m thick 25.3 km 2 square 1m/day regular speed 100 m/day in surging phase Surging periodicities – years At surging passing down on 2 km, breaching Abdukakhor river, m 3 lake rise and catastrophic threats of inudation, floods, sils (mudflows), landslides in Vanch river valley. THE GLACIER ICY 150 m RIVER [15]

25 Surging Glaciers in Tajikistan More than 20 surging large glaciers in Tajikistan [1]. THE REGULARITIES: Ice and snow mass accumulation in the middle or upper part of the glacier, quick shift down the slope, slowing down while slide body spreading on area. The ice and snow accumulation of Medvejii/Khirs and bulging reaches m high.

26 Why glaciers can be fixed? – Because of the volumes are low and bodies are in hard, elastic physical state. Gravity force is low. Why glaciers can move steadily? – Because of the volumes are enough large and the under layers are in viscoplastic state. Bedrock shapes are enough steep and gravity force is enough to drive the glaciers. Why glaciers can surge? – Because of the bedrock profiles have cavities and uneven places, providing accumulation of ice and snow up to the critical values and surging. Why glaciers can be fixed? – Because of the volumes are low and bodies are in hard, elastic physical state. Gravity force is low. Why glaciers can move steadily? – Because of the volumes are enough large and the under layers are in viscoplastic state. Bedrock shapes are enough steep and gravity force is enough to drive the glaciers. Why glaciers can surge? – Because of the bedrock profiles have cavities and uneven places, providing accumulation of ice and snow up to the critical values and surging. Understanding the glaciers: The answers

27 Scientific Problems Whether the glacier layers’ velocity parabolic stratification is true? What are the real boundary conditions on the glaciers’ bottom bedrock surface? Whether the Glen’s law [16] is true and glaciers are really behaving like Newtonian viscous body? What is the proper way towards reconstructions of the global climatic changes and future forecasts? How the glaciers’ movement is responding to the global climatic changes? Fundamental question: how stabilize and protect glaciers?

28 Automatic radio locator system for the monitoring of Medvejii/Khirs glacier (the subject to update): Tajik Technical University. Tel. (992 37) , Fax: Glaciers’ Monitoring System in Tajikistan TajikHydrometeo at the Gvt. RT. Committee on Landuse and Mapping at the Gvt. RT. Institute of water resources and ecology - Academy of Sciences of the Republic of Tajikistan. Institute of Geology, Earthquake Engineering and Seismology - Academy of Sciences of the Republic of Tajikistan. Geology Department - Tadjik National University. Physics Department - Tadjik National University. International joint projects and cooperation. [17]

29 Conclusions 1.The real time monitoring of the large glaciers is very important for studies of glaciers; 2.The remote sensing monitoring of glaciers is effective tool for the prediction and forecasting the related disasters; 3.The qualitative physical modelling of glaciers’ movement promotes adequate understanding and choosing of proper measures towards the forecasts of the sequences; 4.International cooperation promotes data acquisition, analyses, interpretation and taking due measures on global climate changes challenges.

30 References Tajikistan: the nature and natural resources. Dushanbe: Donish, 1982, 602 pp. (Russ.) Glaciers of Tajikistan in global climatic changes. Dushanbe, p. (Russ.) COES RT - Archive Maskaev S. COES RT – Archive Karimov F.H. Viscous plastic model for the glaciers flow (Fedchenko’s glacier as an example). International conference proceedings “Climate changes and natural hazards in mountain areas”, Dushanbe, September 2011, p Aknazarov O. Private communication httpapparat.ccworldshange-earth Cuffey K.M., Patterson W.S.B. Physics of glaciers. Elsevier, 2010, 705 pp Hook R. LeB. Principles of glacier mechanics. Cambridge Univ. Press, 2005, 429 pp Bennett M.R., Glasser N.F. Glacial geology. Chichester, West Sussex: Willey-Blackwell, UK, 2009, 385 pp Geological reference book. Ed. K.N. Pfaffenholz. Moscow: Nedra, v.1, 488 pp. (Russ.) Physical properties of rocks and mineral resources. Chief ed. V.V. Fedynskii. Moscow: Nedra, 527 pp., (Russ.) Vyalov S.S. Ice soil rheology. M.: Strojizdat, 2000, 464 pp. (Russ.) Karimov F.H. Basic Features of the Landslides’ Viscous Flow. Engineering Geology for Society and Territory, Volume 2. Landslide Processes. Eds. G. Lollino e t all. Springer International Publishing, Switzerland, 2014, р Glen J.W. The creep of polycrystalline ice. Proceedings of the Royal Society, London, A228 (1175), 1955, p. 519–

31 Greetings and Thanks for the attention


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