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Seas and Inland Waters of Russia

Three oceans wash the land through many seas. On land, water is found as rivers, lakes, swamps, groundwater, glaciers and permafrost. They are linked: ice melts into rivers, rivers fill lakes and reach the sea, and rain soaks into the ground. Temperature changes all of them.

๐ŸŽฌ Step-by-step story

  1. A block of land. Water is in many places: the salty sea on the right, and fresh water on land. Fresh water means rivers, lakes, swamps, ice and water under the ground.
  2. A river starts high at a glacier or spring, runs downhill and ends at the sea. The blue dots show water moving. Steeper slope gives faster flow.
  3. A lake fills a hollow in the land. A swamp forms on flat, wet land where water cannot drain away. Both slow the water down.
  4. Rain also soaks into the ground and fills gaps in rocks. This is groundwater. A well digs down to it. The cut-away shows the layers.
  5. Glaciers are slow rivers of ice on high land. In very cold places the ground stays frozen all year: permafrost. Ice is stored water.
  6. Free play: slide the temperature. Warm means a smaller glacier, a faster river and thawing frozen ground. Cold means the opposite.

Tip: drag the 3D scene to turn it. Use two fingers to zoom.

๐Ÿค” Common doubts, cleared

Why is the sea salty and rivers are not?

Rivers carry tiny amounts of salt from rocks to the sea. The sea keeps the salt when water evaporates, so it grows salty over time.

Why does a river flow only downhill?

Water moves from a higher place to a lower place because of gravity. The dots speed up on steeper parts.

How are lakes different from swamps?

Lakes are open water in a hollow. Swamps are wet ground full of plants. Both slow the water, but the swamp has no clear open water.

How does water get under the ground?

Rain soaks through soil into the gaps in rocks. A well reaches the water table. Look at the blue layer in the cut-away.

What is the white cap on the mountain?

A glacier. It holds frozen water and feeds the river when it melts slowly.

Why does the river speed up when it is warm?

More ice melts, so more water flows. The slider shows river flow rising with temperature.

Seas

Russia's coast is washed by three oceans through many seas. Seas of the Arctic Ocean (Barents, White, Kara, Laptev, East Siberian, Chukchi) are icy for most of the year. Seas of the Pacific (Bering, Okhotsk, Japan) are on the east. Seas of the Atlantic basin (Baltic, Black, Azov) are in the west and south-west. The Caspian Sea is not connected to the ocean: it is the largest inland body of salty water, so it is called a sea or a lake. Seas give fish, ports and trade routes, but ice makes the north hard to use.

Rivers

A river starts at a source (a spring, a lake or a glacier), flows through a channel, collects water from tributaries and ends at a mouth (a sea or a lake). The land that gives water to one river system is its basin.

Rivers get water from snowmelt (a spring flood), rain and groundwater. Most rivers here freeze in winter and flood in spring.

Lakes, swamps and groundwater

Lakes fill hollows: from glaciers (Ladoga, the largest lake in Europe), cracks in the crust (Baikal) or river flooding. Lake Baikal is the deepest lake on Earth (about 1,640 m) and holds about one-fifth of the world's liquid fresh surface water.

Swamps form on flat, cold, wet land where water cannot drain away, such as the West Siberian lowland. Plants half-rot and make peat. Swamps hold water and slowly release it.

Groundwater is rain and meltwater that soaks into rock gaps. The top of the wet zone is the water table. Wells and springs bring it out. Deep layers of groundwater (artesian basins) can also hold mineral water.

Glaciers and permafrost

Glaciers are masses of ice that slowly move downhill. There are mountain glaciers (Caucasus, Altai, Kamchatka) and ice caps on Arctic islands (Novaya Zemlya, Severnaya Zemlya). Glaciers store a lot of water and feed rivers when they melt.

Permafrost is ground that stays frozen for at least two years, and often for thousands. It covers about two-thirds of the country, mostly in the east and north. Only a thin top layer thaws in summer (the active layer). Buildings are put on stilts so that their warmth does not melt the ground. Warming makes permafrost thaw, which can sink roads and release gases.

Key formulas and definitions

Worked examples

1. The Ob, Yenisei and Lena all flow north. Which ocean do they reach?

The Arctic Ocean. Their mouths are frozen for many months of the year.

2. Why are houses on stilts in permafrost areas?

A house on the ground heats the soil and melts the ice in it, so the ground sinks. Stilts leave air under the house so the ground stays frozen.

3. Why do many rivers rise in spring?

Winter snow melts, and the meltwater flows into the rivers all at once. This is the spring flood.

4. Why is Lake Baikal special?

It is the deepest lake on Earth (about 1,640 m) and holds about 20% of the world's liquid fresh surface water.

Common mistakes

Practice quiz

1. Which river is the longest in Europe?
2. Which lake is the deepest on Earth?
3. Ground frozen for two or more years is called:
4. The Lena flows into:
5. Water found in rock gaps under the ground is:

Practice: answer these yourself

Type or choose your answer, then press Check. Use a hint if you are stuck; the full solution appears after you answer.

Frequently asked questions

What is permafrost?

Ground that stays frozen all year for at least two years. Only a thin top layer melts in summer. It covers about two-thirds of the country.

Why is Lake Baikal so deep?

It lies in a deep crack (rift) in the Earth's crust, which is still slowly widening. This crack holds a very deep basin.

What is the difference between a lake and a swamp?

A lake is open water in a hollow. A swamp is wet, flat ground full of plants and peat, where water cannot drain away.

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