Western Siberia- Physical Setting

Western Siberia is the area between the Ural Mountains and the Yennisey River, and comprises the West Siberian Plain and the mountains to the south (parts of the Altai and Sayan Mountain Ranges). All told, this is an area of roughly 1.2 million square miles (for comparison Alaska is 586,400 square miles and Kansas is a mere 82,282 square miles).

Google Earth Image

The West Siberian Plain is the largest and flattest plain on earth. Actually, it is somewhat concave, because the soft soils were compressed under glaciers. This concave shape, combined with the fact that the Ob flows northward, produces huge ice jams and a great deal of springtime flooding throughout the mid- and lower reaches of the Ob.

The Ob River is the fifth longest in the world when measured from the headwaters of the Irytsh (5,410 miles); when measured from the headwaters of the Katun it is 3,650 miles long.

Down south, upriver near Barnaul, the river thaws in late April, while up north, near its mouth, the Ob doesn't thaw until early June. This means that when the upriver reaches of the river thaw in the spring, the melt water meets an ice jam and backs up into the lowlands.





   Above: Ice jam in the mouth of the Ob River as it enters the Kara Sea NASA
   Left: bottom is the Ob River in the fall, top is the flooded Ob River in summer. NASA






The gigantic marshland that is formed by flooding in the lowlands is one of the reasons why it is so difficult to get across Siberia. But it is also the reason that there is so much oil and gas. Geologically, the basement structure came into being 1.6-1.7 billion years ago and has undergone prolonged subsidence and deposition, resulting in Mesozoic-Cenozoic basin fill on top of a Paleozoic basin. The 66 fields discovered since the 1960s in the northern West Siberian basin contain at least 22 trillion m3 of proved gas, which is almost 1/3 of world's reserves. Half of these fields are giants (> 85 billion m3) and include the largest and second-largest gas fields in the world.

You can see the location of the fields in the Google Earth night view below (NASA Earth City Lights from the Google Earth Gallery) as well as the location of the Kuzbass coalfields and the Trans-Siberian Railroad, all of which are lit up while the rest of Siberia is without conspicuous artificial lighting. (You can explore this in the Google Earth KML file in the attachment section at the bottom of the page.)



The Katun, Biya, and Ob Rivers and Lake Teletskoye in the Altai Republic

In contrast to the marshy lowlands of the middle and lower Ob River, its headwaters are in rocky mountainous regions to the south.

Left: location of proposed dam on the Katun River (only partially completed). The Katun joins the Biya River to form the Ob just north of the Altai Republic near the city of Biisk.

The proposed dams on the Katun River were part of the effort by Soviet planners to divert water from Siberian rivers to supplement the flow to the Aral Sea.

In the opinion of many experts, this proposed implementation would have resulted in many adverse conse- quences including: (i) flooding of agricultural lands and forests by water reservoirs; (ii) increased level of sub-soil waters along the channel, causing flooding of nearby set- tlements and roads; (iii) negative impacts on valuable fish species in the basin of the Ob’ River; (iv) an unpredictable change in the permafrost regime; (v) climate change and change of ice cover in the Gulf of the Ob and the Kara Sea; (vi) formation of bogs and saline soils in Kazakhstan and Central Asia; and (vii) changes in the local flora and fauna.1


In addition, a great many significant cultural resources would have been lost. The combination of scientific, cultural, and Indigenous values sparked a massive protest against the dams in the final years of the Soviet Union. We documented this in our paper The Sacred and the Scientific: Traditional Ecological Knowledge in Siberian River Conservation

Lake Teletskoye drains into the Biya River, which along with the Katun, forms the headwaters of the Ob River. Like Lake Baikal, Lake Teletskoye is a rift lake with a single outflow river (the Biya). 


 Lake Baikal

 Lake Teletskoye

 
Lake Baikal is the oldest (still existing) freshwater lake on the planet (over 25 million years old). It is also the deepest continental body of water (5,315 feet). It is the largest freshwater lake by volume (5700 cubic miles), and it contains 20% of the planet's fresh water. It has a maximum width of 60 miles and a length of 389 miles. Lake Baikal is completely surrounded by mountains and has over 300 rivers and streams draining into it, but only one (the Angara River) flows out of it.
 
Lake Teletskoye is estimated as 320,000 years old (compared to the average for freshwater lakes which is approximately 20,000 years). It is one of the 25 deepest lakes in the world (1066 feet deep). It is 48 miles long, 3 miles wide, and 90 square miles in surface area and has a volume of 9.6 cubic miles. Lake Teletskoye is completely surrounded by mountains and has 70 rivers and 150 streams flowing into it, but only one (the Biya River) flowing out of it.

Both Lake Baikal and Lake Teletskoye are rift lakes that continue to spread with tectonic movements.






Sources

1. Aharon O., I.S. Plotnikov, S. Sokolov and N.V. Aladin (2010). The Aral Sea and the Dead Sea: Disparate lakes with similar histories. Lakes & Reservoirs: Research and Management 2010 15: 223–236.

2. Rift Lake image  http://www.gly.uga.edu/railsback/DPT/1121DivergPTBndries08.jpg

3. De Batist, M., Canals, M., Sherstyankin, P., Alekseev, S. & the INTAS Project 99-1669 Team (2002): A new bathymetric map of Lake Baikal. Scientific Drilling Database (SDDB). doi:10.1594/GFZ.SDDB.1100.


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Dr. Cynthia Annett,
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