Лучкин Костя

9 в

2011

Contents

Baikal. Gas and Oil.        

Lake Baikal        

Gas-mud Volcanoes        

Natural Gas        

Earthquakes        

Gas Hydrates        

Chemical Synthesis and Photosynthesis        

Catastrophic release of methane        

Oil        

Conclusions        

Baikal. Gas and Oil.

Lake Baikal

Baikal is undoubtedly one of the miracles of nature known all over the world. Everybody knows that Baikal is the deepest lake in the world, containing the large amount of fresh water. In my project I’ll try to discuss the research of gas and oilfields around Baikal and at its bottom using  bathyscaphes of "Pisces" and "Mir".

Lake Baikal is in a rift valley, created by the Baikal Rift Zone, where the crust of the earth is pulling apart. At 636 kilometres long and 79 km wide, Lake Baikal has the largest surface area of any freshwater lake in Asia (31,722 km2/12,248 sq mi) and is the deepest lake in the world (1,642 m/5,387 ft). The bottom of the lake is 1,186.5 metres (3,893 ft) below sea level, but below this lies some 7 km (4.3 mi) of sediment, placing the rift floor some 8–11 kilometres (5.0–6.8 mi) below the surface: the deepest continental rift on Earth. In geological terms, the rift is young and active—it widens about two cm per year. The fault zone is also seismically active; there are hot springs in the area and notable earthquakes every few years. The lake drains into the Angara tributary of the Yenisei.

Its age is estimated at 25–30 million years, making it one of the most ancient lakes in geological history. It is unique among large, high-latitude lakes, in that its sediments have not been scoured by overriding continental ice sheets. U.S. and Russian studies of core sediment in the 1990s provide a detailed record of climatic variation over the past 250,000 years. Longer and deeper sediment cores are expected in the near future. Lake Baikal is furthermore the only confined fresh water lake in which direct and indirect evidence of gas hydrates exists.

Gas-mud Volcanoes

During the expeditions on bathyscaphes  "Pisces" in 1977, 1990 and 1991 so-called gas-mud volcanoes were found at the bottom of Baikal.

Scientists expressed different opinions on the mechanism of formation of gas-mud volcanoes. They supposed that these volcanoes are active now. The researchers  informed about the facts of "eruption" of gases from muzzles of such volcanoes. The eruptions were seen as  fiery columns. The flame rises to 18 meters over the  water level. By the way, that can be a solution of the mystery of “shining Baikal”. When the local people see the strange phenomena of fire above the water at night, they sometimes connect it with UFO and aliens.

Natural Gas

There are exits of gases in natural state everywhere on the lake. In summertime it is emerging bubbles of «air», in winter — the emptiness in ices. If you break a crust of ice and  set fire then the gas will ignite and will burn for a couple of minutes. Because of such emptiness with gas the movement across winter Baikal is dangerous. The destructive action of gases on  ice in winter can be seen in many areas, especially between Goloustnoj and Posolskoe. This way was used for centuries as a winter road between the two coasts. And so a lot of accidents took place there when transports with goods and passengers disappeared under the ice.

For the same reason Baikal in this place freezes later and melts earlier. The huge ice-hole between a mouth of Selenga and the area Goloustnoe — Buguldejka can be seen in a space picture of 1977. Several years  later the same open space of black water among white ice, was observed from a board of the high-rise jet plane,  though it was February with its frosts and winds.

If you try to make a map of the bubbles  of deep gas, frozen in the ice, it is possible to receive an interesting picture of their location and to understand their origin. If they have linear character, then they are most likely connected with tectonic breaks. If they are all near the river mouths their origin is caused by the disintegration of the died off microorganisms. However, the presence of gazo-mud volcanoes at the bottom of Baikal lets us connect this phenomenon with tectonics.

Earthquakes

The water and gas warming up can occur only during their contact with the Earth mantle substance through muzzles of underwater volcanoes. In the mouth of Selenga, for example, during catastrophic earthquake of 1862 200 sq. km of Tsagansky steppe disappeared under the water. (nowadays the bay Proval). There were 5 Buryat settlements on that territory and people saw hot water running from the formed cracks in the earth. They also saw the flame which burnt some buildings.In August of 2008 an expedition of two bathyscaphes  "MIR" came to Baikal.

One of the aims of this expedition was  to study a volcano "MALENKIY", found in the deep part of the lake near the river  Selenga. In this area in spring of 2003 a dark spot on the ice of Baikal about one kilometer in diameter was registered from space. Later the sonic depth finder showed an underwater anomaly. It was a torch of 500 meters height. And in 2008-2009 from boards of "MIR" scientists at last saw oil and gas coming  to light through cracks in the bottom on the depth of 900 meters.

In 2009 scientists found one more mud volcano — St.-Petersburg. In 2005 the gas torch of 900 meters height escaped from its muzzle from the depth of 1400 meters.

Gas isn’t a new phenomenon for Baikal. In 1931 4 gas fields were found on the east coast of the lake. Most powerful of them settled down near Posolsk. But industrial use of the gas fields wasn’t a success. In gas, for example, there  was more air, than combustible substances.

Gas Hydrates

And what about natural gas in deep points of Baikal ? Does it have any differences? It was proved that it has special rather essential features. Today it is known that "deep" gas in the seas and oceans exists as gas hydrates. It looks like usual rather dirty slices of ice or the white powder reminding snow where gas molecules are connected with water molecules. However, if we lift crystals of hydrates to the surface of water, they melt immediately and burn with a dark blue flame.  High pressure of water and low temperature in deep layers are conditions necessary for  their existence.

Gas hydrates are crystalline water-based solids physically resembling ice, in which small non polar molecules (typically gases) are trapped inside "cages" of hydrogen bonded water molecules. In other words,  hydrates are  compounds in which the host molecule is water and the guest molecule is typically a gas. Without the support of the trapped molecules, the lattice structure of hydrate  would collapse into conventional ice crystal structure or liquid water. Most low molecular weight gases (including O2, H2, N2, CO2, CH4, H2S, Ar, Kr, and Xe), as well as some higher hydrocarbons and freons will form hydrates at suitable temperatures and pressures. Gas hydrates are not chemical compounds as the sequestered molecules are never bonded to the lattice. The formation and decomposition of  hydrates are first order phase transitions, not chemical reactions. Their detailed formation and decomposition mechanisms on a molecular level are still not well understood.

Naturally on Earth gas hydrates can be found on the seafloor, in ocean sediments, in deep lake sediments (e.g. Lake Baikal), as well as in the permafrost regions. The amount of methane potentially trapped in natural methane hydrate deposits may be significant , which makes them of major interest as a potential energy resource.

For the first time gas hydrates on Baikal were found by A.M. Сагалевич in 1977 during deep-water works of bathyscaphes "Pajsis". Uniqueness of the discovery was  that they were found on the bottom of a fresh midland lake. In 2008 the scientists wanted to find out whether gas hydrates can be found only near the cones of gaso-mud volcanoes or on the whole bottom over tectonic cracks.

When the plan of scientific researches of the "World" was discussed, this problem got priority support of scientists of expedition. Probably,  because gas hydrates are a promising kind of fuel. More than 20 % of world's reserves of fresh water and considerable (yet not established) quantity of hydrocarbons are concentrated in Baikal. One centimeter of gas hydrates gives 164 cubic meter of pure methane.

When someone works out technology of extraction of gas from firm crystals, he’ll become a multi-billionaire. The problem is that the gas disappears if it gets into warmer water and normal atmospheric pressure.

In 2009 there was such an episode: a piece of gas ice was picked up by bathyscaphes "World" and  they began its lifting to the surface. But at the depth of 200 meters, gas hydrate unexpectedly blew up and disappeared. However scientists celebrated a victory. They found out the extensive fields of  "firm" gas not only under a layer of ground deposits, but also on their surface in the form of ice floes.

Here are some points about gas hydrates  from the Program of scientific researches of Baikal with bathyscaphes  "Worlds":

1. Gas hydrates are fuel of future. 1 % of gas hydrates after their transformation into gas can supply the whole world with pure combustible fuel with the least greenhouse effect.

2. It is necessary to know background level of hydrocarbons in Baikal to be able to estimate pollution by hydrocarbons correctly.

3. The exact knowledge of hydrocarbons of Baikal will allow to predict sharp emissions of hydrocarbons at fast warming of  climate.

But first of all hydrates in the conditions of fresh water must be studied. As the head of expedition Arthur Tchilingarov explained to journalists in 2008, gas hydrates in the future can replace exhausted resources of oil and gas. But today the aim of scientists on "Worlds" is to estimate these resources and possibilities of their production in the future, without breaking ecological balance. First of all deep-operating vehicles have to investigate places of location of geothermal sources and mud volcanoes, they will define background level of hydrocarbons for  estimation of pollution, work out the mechanism of forecasting the new points of gas outcome from deep ground sedimentary layers. It is important to understand the mechanism of gas outcome to the surface, formation of gas hydrates and their dissolution in water.

So, now geological and geophysical methods define the basic laws of distribution of gas hydrates in deposits of World ocean and in the lake Baikal. It was proved that their existence is connected to mud volcanoes. Such structures are found with the help of multibeam bathymetric sonar investigation of the bottom, shooting of a surface by a locator of the lateral review, seismoacoustic profiling and other scientific methods, but remote criteria of detection of gas hydrates location in deposits and technology of their production  aren't developed yet.

That’s why the discovery of gas hydrates close to surface of the bottom of Baikal easily accessible for studying is very important. Using of bathyscaphes "World" will allow to find exact places of gas and oil location at the bottom of the lake, to define an estimate their influence upon the lake ecosystem. Besides, there exists an opportunity of visual observations of the process at the bottom of Baikal.

Chemical Synthesis and Photosynthesis

Long-term researches of concentration of methane in Baikal showed that, despite the big size of emissions of methane in the water, its concentration is insignificant thanks to activity of microorganisms. Their life is probably based on chemical synthesis. As you know, we get energy from plants, while plants produce energy from carbonic gas using the sunlight. The process is called photosynthesis. During chemical synthesis microorganisms get energy from chemical reactions. They don’t need sunlight to live! Their studying is  very important as it can give a possibility to solve the evolution problem, especially adaptation of live beings to various ecological conditions. Scientists hope to discover such communities of microorganisms in Baikal.

Catastrophic release of methane

Gas hydrates, in great quantity reaching surfaces of the seas and oceans, can become real murderers. Catastrophic release of methane from the decomposition of such deposits may lead to a global climate change, because CH4 is more efficient greenhouse gas even than CO2 . The fast decomposition of such deposits is considered a geohazard, due to its potential to trigger landslides, earthquakes and tsunamis.

«The Bermudas triangle» in Atlantic is a good example of this natural phenomenon. Gas coming from an ocean bottom is, probably, the reason of the planetary accidents connected with liberation of methane from breaking up gas hydrates at the bottom and under it.

As we spoke above, at high pressure and low temperature the water containing methane gets structure of the firm substance similar to snow or ice. But if temperature  raises, the firm condition of substance becomes flying gas. Then huge volumes of methane are thrown out from oceans into the  atmosphere. In «the Bermudas triangle» such process is caused by a warm current of Gulf Stream. The forming gas breaks through thickness of water (4 and more kilometers!) and causes the unusual atmospheric phenomena. First of all, water foams: the ships in such "foam" lose buoyancy and sinks.

Secondly, bubbles vibrate on frequency of ultrasound, and that badly influence on people, causing panic. People easily can jump into the water, they don’t realize the situation. Probably, that was the reason of legends about the mysterious ships-phantoms («flying Dutches») left by their crews. Moreover, the friction of billions rising bubbles electrify the water and causes the local change in the magnetic field of the earth: planes in such conditions easily lose their course. The pilots of the lost planes also reported, that in the mist they couldn’t distinguish the sky from a water surface and didn't see horizon. It is possible to explain this by rising with bubbles of gas  moisture.

But all these phenomena  are connected with Gulf Stream, carrying warm streams of water to cold ground layers of the arctic zone of Atlantic ocean. But in the conditions of global warming of climate the emissions of methane from a bottom of the seas and oceans will accept avalanche-like  character. More than that, methane is among some hotbed gases and can add to the warming effects. Some scientists suppose that catastrophic climate changes in the past could be caused by  abnormal emissions of gas hydrates.

Transparent lumps of ice were found by the doctor of mineralogical sciences Valery Peresypkinym during the previous immersing of bathyscaphes , and their samples are stored in laboratory in waterproof  vessels with liquid nitrogen.

Oil

Oil is often found near gas. People called it "mountain gum» or «mountain wax». It was found on Baikal since ancient times, especially after strong earthquakes and storm. In the summer of 1772 academicians I.G.George and I.G.Gmelin found such pieces of oil swimming on lake and carried by waves to coast.

Such pieces are often can be seen on a shore of the southern part of Baikal, but many people consider them to be pieces  of asphalt from periodically destroyed highway on northern slope of Hamar-Daban. Fishermen used to produce quite good turpentine and lubricant substances for impregnation of ropes, networks and boats from such pieces, but till now they complain that such pieces damage their  nets. Local medicine recommend to treated  illness of feet with this substance.

However long-term prospecting works have shown that on the banks of Baikal  there aren’t any oil and gas fields that can be used in industry.

Nevertheless, oil exists on Baikal and effects its ecology. Its frightening spots as large as one kilometer in diameter, are periodically fixed from satellites. Scientists proved that only on the Olhovsky break 4 tons of oil comes to surface  (in a scientifically way "unloads") every year. Nevertheless, despite constant emissions, the pollution area for some reason doesn't increase. Deep-water immersing of  "Pisces" discovered that in the mouth of river Barguzin  there is the permanent  spot of oil which comes to the surface through powerful sedimentary layer .

The immersing "Worlds" confirmed the conclusions of the previous explorers. On the depth of 850 meters they found an active source of oil "eruption". However, the  fountain of oil wasn’t found, as the water was very muddy in this place. The bottom was covered by cracks and breaks through which, obviously, oil can come out. Later some "constructions" from bitumen to 10 meters high were found on the bottom of Baikal. They were similar to volcanic cones from which fat black oil bubbles were rising a drop after a drop.

Sometimes fields from bitumen occupied extensive spaces. Investigating them, "Worlds" were so soiled that it was necessary to invite a special brigade of cleaners , but they didn’t managed to cope with a problem. «Мир-2» continued its work with oil spots on its sides. It seems strange, but t these spots weren't washed off by the Baikal water for two weeks of work.

Olga Shubenkova, the researcher from “Mir” shares her impressions:

1.  Heavy fractions of oil, settling near funnels, formed unusual constructions of bitumen in height to 10 meters. Their detection was a fantastic moment. We were moving along the flat bottom, and suddenly something strange appeared before the eyes. It was coral-like, all covered by white huge planarias and various sandhopper.
2. At the bottom of Baikal the animals are white, they have no pigment because the sunlight doesn't get to such depth. We observed, how the bubbles of gas covered with oil, were rising from deposits to the surface. In process of emersion the gas was dissolved, and the oil transformed in small balls which form an oil spot on the surface of Baikal.

The pilot of "Mir" Evgenie Tchernyaev adds:

— Oil "Unloading" is an unforgettable show. It looks like the boiling teapot, buried in the bottom. The garland of bubbles rises upwards. Some scientists call them lake beads.

The Corresponding member of the Russian Academy of Sciences Arnold Tulohonov said

— Among three major discoveries of world level the most important is the oil emission which makes to revise classical theories if its formation. Most likely, oil is formed not only in the places with organic residues. On the depth of 850 meters bitumen structures (heavy fractions of oil)were found. Their samples were taken by scientists for the further studying. Such structures were not found before.

Another important discovery is close symbiosis and coexistence of live organisms with oil in the conditions of Baikal. This is a new word in science.

The head of laboratory of microbiology БНЦ Siberian Branch of the Russian Academy of Science Bair Namsaraev  added:

— The bitumen "constructions" where oil comes out, are also dwellings and essential source of reproduction of the microbes destroying this oil.

Conclusions

Thus, natural exits of oil don't pollute Baikal. Baikal isn't simple a reservoir with great amount of water, it is a live organism, capable for self-cleaning and self-control. The biological mechanism of self-cleaning works without any failures. Both water and the bottom surface of a huge fresh lake remain  crystal-clear.

References

1 А. Тиваненко «Тайны Байкальских глубин» Чита 2009.

2 С. Волков «Вокруг Байкала» Иркутск 2006.

3  http://en.wikipedia.org/wiki/Lake_Baikal

4 http://en.wikipedia.org/wiki/Gas_hydrate

5 http://ru.wikipedia.org/wiki/Planariidae

6 http://ru.wikipedia.org/wiki/Байкал

7 http://ru.wikipedia.org/wiki/Землетрясение_на_Байкале_(2008)

8 http://ru.wikipedia.org/wiki/Экспедиция_«„Миры“_на_Байкале»

9 http://ru.wikipedia.org/wiki/Грязевой_вулкан