by Academician Vladimir KOTLYAKOV, Director of the RAS Institute of Geography

Geography is among the seven oldest natural sciences. Appearing in ancient times, it has passed important development stages and now largely relies on space data and geoinformation technologies. This article is about one the recent achievements of geography--the discovery of the subglacial lake Vostok in the Central Antarctic, and of the cyclical pattern of the Earth's evolution. It lists the basic objectives and development trends in present-day geography.

IS GEOGRAPHY NEEDED IN THE 21st CENTURY?

Ever since my college days in the early 1950s, I have been amazed at the surprising skepticism of some expert geographers with regard to their profession. One could hear complaints like this: "Is geography needed to people at all when all natural objects on the planet have already been discovered and the terrestrial surface is constantly monitored by hundreds of space vehicles flying around the Earth?"

Such questions have always perplexed me. I cannot imagine a single construction projects started without a detailed study carried out by competent geographers; or a natural-technogenic catastrophe like a disastrous drought, flood or forest fires studied in the absence of comprehensive geographical data.

Traveling once in the United States, I visited a company specializing in the environmental and geographical examination of major objects to be built in absolutely different natural conditions. The head of this compa-

ny said that such studies are carried out for a rather long period of time and require specialists in different fields of knowledge: geologists, hydrogeologists, geophysicists, biologists, archeologists, and so on. According to the company's owner, the last line of an examination is always the responsibility of geographers, since only those who have a comprehensive geographical background can get to the brass tacks, find a consensus among experts and draft a final statement recommending or not recommending this or that building project. The reason for such distinction of geographers lies in the substance of geography as a science--a broad and comprehensive discipline embracing both natural and social sciences.

GEOGRAPHY-ONE OF SEVEN FUNDAMENTAL SCIENCES

The science of geography was born in the dim and distant past, as early as in the Ancient Egypt and Mesopotamia--a man always wanted to explore the environment he lives. When navigating by nearest rivers and along seashores, he should know where he is, keep in mind the scenes, classify and sort out places. These were the underlying reasons for establishment of geography. In Ancient Greece, in the summer of sciences and arts, geography followed astronomy and formed its own scientific research basis; ancient Greek philosophers, for example Anaximander and Anaximen, as early as in the 5th century B.C. already developed the ideas of geographic integrity of the ancient world, and Anaximander created the first map and attached it to his work "On Nature", which gave birth to the ancient mapping..

Thus, geography became the second fundamental natural science after astronomy. The seven such sciences are in that order: astronomy, geography, mathematics, physics, chemistry, biology and geology. Each science has its own subject of study. Geography studies the outer shells of the Earth: atmosphere, hydrosphere, cryosphere and anthroposphere, i.e. territorial characteristics of human household and human activity.

So far as geography developed and accumulated data, it, as any other science, became more complex and explored new areas of knowledge. The main two wings of geography--physical and socio-economic--enriched with new development lines, which made it possible to deepen knowledge on the regularities of nature and economics.

For the passed centuries geography expanded significantly its borders and become useful to a man. Geography experienced the epoch of great geographical discoveries (16th-18th centuries), epoch of exploration of remote and difficult of access areas (19th century-early 20th centuries), epoch of space observations (late 20th century) and epoch of remote explorations of the Earth (late 20th century-early 21st centuries).

In 2000-2007 Prof. A. Kostomarov (Moscow State University) developed a five-language academic dictionary and managed to split all existing geographical data by 14 main subjects, each of these subject, in turn, can be split into minor entries.

Separate branches of geography do have much in common: acts of nature occurring on the land surface and in the ocean are mutually dependant and the form the face of the Earth; the main processes that take place on the planet are affected by the external source of power, the Sun, and terrestrial sources that are the objects of geography.

The "miracle" of geography is that it is the only fundamental science that has both natural science and socio-economic elements. The underlying basis of geography constitutes a simultaneous exploration of all

sorts of natural and social processes irrespective of their spatial differences. Although the social element of geography has its own sub-natural logic of development, it is also dominated by the regularities of nature. Predetermination typical of nature is more or less inherent to all fields of social life at any phase of human development, since man is a part of evolution and nature and can lives only in a constant exchange with it. That is why social laws are based on the laws of nature, which makes them very close to the rules of natural sciences and makes geography an integrated single science.

In the aforementioned dictionary, we offered a brief definition of geography. It is a complex of sciences studying natural and anthropogenic events on the surface of the Earth and in the surrounding environment, their spatial distribution and variation in time. This definition asserts an everlasting value of geography and its eternal development as any other fundamental science.

Practicability of global structure and its elements, as well as the problem of eternal development of science, is a philosophical issue. It is really exciting that water, after freezing, converts into ice that weighs 10 percent less and forms a floating cover protecting rivers and water bodies from straight freezing and hence saving life forms irrespective of regular freezing seasons.

LAST GEOGRAPHICAL DISCOVERY OF THE 20th CENTURY

Fast development of space methods in the 20th century resulted in new geographical discoveries. On the first pictures taken by space vehicles we could see huge ring-type structures of terrestrial relief that puzzled geomorphologists. Next came subglacial lakes discovered in the Antarctic. Since I was directly involved in this geographical discovery, I'd like to consider it in more detail.

In the early 1960s, one of my subordinates I. Zotikov proved in theory that there is a critical thickness of a glacier, that, if exceeded, triggers ice melting at the glacier bed. According to his calculations, despite of very low average annual temperatures, a continuous ice

Tree of geography.

melting should occur at the bed of almost all Central Antarctic.

In 1959 and 1964, after an echo sounding in the Central Antarctic, A. Kapitsa obtained seismograms showing two reflections near Vostok station at the depth of 3,730 and 4,130 m. That time, the upper reflection was taken for the reflection from the glacier bottom, and the lower reflection was attributed to the border of diluvium and bedrock. But further analysis revealed that we likely found, and now we are absolutely sure of it, a water layer of over 400 m, not diluvium.

In the 1970s, the Scott Polar Research Institute completed a comprehensive radio sounding flight program in the Central Antarctic and contoured big water bodies called subglacial lakes. In the 1990s and 2000s, thorough airborne geophysical studies were carried out in this region by national and American specialists who measured the dimensions of this vast subglacial lake named Vostok: length-230 km, width-50 km, surface area--about 10,000 km; thickness of ice over the lake-approximately 400 m, water volume-6,100 km³.

Ice creeps down from the West and at about 3,550 m proceeds to float, moves by the water surface and runs into the eastern lakeshore where it reinstates the characteristics of ice sheet. The surface relief at the edge of the lake is well rugged, which speaks for complex processes in going ice from creeping to floating and vice versa. Therefore, a huge mass of ice rising above the lake may be treated as a kind of ice shelf. All that is absolutely new natural phenomenon, a real epoch-making geographical discovery.

DEEP ICE WELL

AT VOSTOK STATION

Vostok station was set up and opened in the early 1958, during the International Year of Geophysics, when I spent 13 months on the Antarctic continent. There, in the Central Antarctic, at the height of 3,490 m above sea level, the average annual air temperature is ~55.5 °C, the average annual precipitation is only 23 mm-it is a real polar desert. The ice thickness is about 3,700 m; consequently, it is made of ice accumu-

lated for some hundred thousand years. The isotope profile of the well being drilled at Vostok station makes it possible to obtain data on the temperature conditions in the polar regions for the last 420,000 years and make important conclusions.

First, the concentration of greenhouse gases and global temperature of the past changed concurrently, but in the recent 100 years the gas content increased dramatically, while temperature changes are within natural fluctuations. Second, the Holocene's climatic optimum is 1,5-2°C lower than the maximum temperature of the preceding interglacial period when no anthropogenic effect could be on the Earth. Third, the Holocene, a period that has been lasting on the planet for about 11 thous. years, is much longer than four preceding interglacial periods and will probably change for a new ice age in the nearest geological future.

Ice ages of the period are characterized by general climatic cooling and harsh contrast between different latitudes, land and sea and, consequently, increased power of all ocean and atmosphere processes. In the periods of global cooling, ocean and atmosphere streams intensified, cyclonic processes on the edge of ice sheets became more active. Intensified atmospheric circulation during ice ages was proved by measurements of content of continental and sea aerosols in the ice core taken from the well.

Continental microparticles are represented by dust from deserts, rock weathering products, ammonia sulphate formed of SO₂ and NH₃ over the continents. Sea microparticles appear as a result of bubble breaking in white caps formed by stormy wind on the sea surface. Due to their big size, solubility and quick formation of clouds, they leave the atmosphere in no time. This is why reason why the bulk of microparticles in the medium and upper parts of the troposphere is represented by continental particles, and it is they we find in the sheets of polar and mountain glaciers located high above sea level. Study of deep ice core is the only way to modify characteristic features of the atmosphere of the past, in particular, the main biogenic cycles of carbon, sulphur and nitrogen.

Aluminum and natrium aerosol are a typical indicator. Concentration of these substances increases during ice ages. Content of continental dust and sea aerosols in the Pleistocene ice, taken from the well at Vostok station, is 70 and 5 times higher respectively than in the Holocene ice. The main reason for that is strengthening of winds resulting from the increasing latitude contrast. Deserting of preglacial areas and their expansion due to dewatering of the shelf accompanied by eustatic lowering of the sea level (as much water made part of the ice cover) played an important role in these processes.

Thus, all measured and analyzed chemical parameters of the ice core led us to the conclusion on the drastic increase of dust content in the atmosphere and concurrent intensification of longitudinal circulation during age, which is attributed to the increased temperature differences between polar and equatorial belts of the Earth. Moreover, atmosphere dustiness is itself a powerful climate-forming factor: an increase in the dust content during age period contributes to further cooling.

This was confirmed by specialized research carried out by climatologists exploring consequences of nuclear war ("nuclear winter"). Injection of huge masses of dust and ash weighing up to billions of tons would be the main after-effect of nuclear explosions. According to the results of simulation, dust and ash will quickly envelope the Earth, which will decrease the atmosphere transparency for solar radiation by 75-200 times. This would lead to the heating of the upper troposphere and fierce cooling of its bottom layer (by 15-30 ºC). Local effect could be even more striking resulting in cooling down the air above the temperate

Core relief of the subglacial lake Vostok:

1-isoheights of the core relief, m; section of the isometric lines 150 m;

2-sea level;

3-coastline of lake Vostok.

zones of the Northern hemisphere by 40-50 °C. This implies that increase of dust and aerosol content in the atmosphere, in turn, contributed to these coolings--a positive reaction originated between two these processes.

A similar model of development is offered by nature itself. In the course of eruption, some volcanoes discharge many cubic kilometers of ash and other impurities to the atmosphere. For example, in 1883 Krakatau (Java Island) emitted 18 km of dispersed products. Tambora volcano (Subawa, Indonesia) that erupted in 1815 discharged even more dust material. It was the most powerful eruption on the Earth for the last 500 years. Emissions to the atmosphere increased manifold the consequences of the abovementioned eruption of Krakatau. Gas and emissions penetrated even the upper layer of the atmosphere and formed a screen that reflected sunbeams, which resulted in a deep cooling in the temperate latitudes and the snow cover persisted till mid June, in Western Europe first frosts were registered as early as in August. That year there was no summer at all in England, the country had to survive as no harvest was grown...

Impressed by this natural phenomenon, in 1816 an English poet George Byron wrote a poem; in 1854 Russian writer Ivan Turgenev published an essay called The Darkness, written after Byron's poem:

...The world became a desert;

That crowded and mighty world Turned out a dead bogy without grass and trees,

...Winds stuck in a silent air...

Clouds disappeared... the darkness didn't need Their help... it was everywhere...

According to simulation experiments, such winter lasts about two years. But, unfortunately, models do not

Changes of temperature, content of greenhouse gases and aerosols in the ice core taken from the deep well at station Vostok, covering 420,000 years.

Downwards: 1-CO2 content; 2-deviation of the temperature from present-day level; 3-CH4 content;

4-natrium content in the ice; 5-dust content in the ice.

have all stability mechanisms typical of the real atmosphere. After the "nuclear winter" the climate may never reestablish its former characteristics.

Glaciological and oceanological data demonstrate a cyclic character of climatic fluctuations that reflect astronomical factors analyzed in due time by Milankovich. Thus, cyclicism is a typical characteristic of natural environment. Over a million years the ice age has been reigning over or planet, characterized by alternating glacial and interglacial conditions.

Nevertheless, irrespective of the scale of anthropogenic effect on the climate, it exists simultaneously with the natural climatic fluctuations that are still much more powerful than effect resulting from emission of greenhouse gases. Some data confirm that in the past the climate changed drastically compared with the period of measurements, i.e. for the last 150 years. As for the climate of the passed periods, scientists registered significant variations in the lake levels, river regimes, also found out extreme droughts and floods. If they repeat in the future, this will lead to severe socio-economic consequences, not all social and economic systems will be able to adapt to them.

PRESENT-DAY TASKS OF GEOGRAPHY

Today geography faces a wide range of tasks. A system of geography-oriented institutes was established within the Russian Academy of Sciences. First of all, it includes institutes of geography in Moscow, Irkutsk and Vladivostok, institutes of water and environmental problems in Moscow, St. Petersburg, Petrozavodsk, Barnaul and Khabarovsk, the Institute of Plains in Orenburg. All these

institutes focus on the urgent problems of geography, including the following sets of problems.

Paleogeographic studies are to reconstruct and forecast climatic and geoecological changes in the natural environment of the Northern hemisphere and the Arctic Region on the basis of scientific data obtained in the course of study of the Pleiocen, Pleistocene and Holocene events, as well as assess effect of the natural and anthropogenic elements on the climatic changes. Scientists monitor how landscape systems and their components react on climatic changes by way of pale-osimulators and modeling, research evolution of landscapes in terms of anthropogenic transformation of the environment. On the basis of data for the Pleistocene and Holocene, scientists research adaptive capabilities of a man to extreme states of geogystems in the epochs of global climatic extremes.

Physical mechanisms of climatic changes in the global and regional scales are under research, including processes of long-period changes (deep-sea circulation, fluctuations of glacier sheets, etc.). Scientists explore mechanisms that form spatial fields of climatic characteristics of the Northern Asia in different time periods. Space and time characteristics of expected global and regional changes of the climate on the basis of paleoanalogues of the preceding geological epochs (Pleistocene and Holocene) are compared against the results of numerical simulation.

Scientists are planning to research mechanisms forming spatial fields of climatic characteristics of the Northern Eurasia in different epochs. For this purpose analysis of spatial fields in different periods from the Mikulin interglacial to the climatic optimum of the Holocene and historic period will be carried out; they have also scheduled analysis of ocean surface temperature filed formation and ice propagation; numerical simulation of climatic characteristics of the Northern Eurasia for different time periods; comparing spatial data obtained by way of simulations and modeling based on the field data.

The framework for a complex monitoring of the environmental conditions, including atmosphere, hydrosphere and cryosphere, is developed; climatic and ecological consequences of natural catastrophes are modeled. Scientists research changes in the elements of the heat, water and carbon balance in different on-land ecosystems in the result of climatic changes and human intervention. They estimate, forecast and prevent negative aftereffects of deserting and droughts, including problems of salt accumulation in the landscapes of arid regions.

New research methods, technologies, equipment and analytical methods to study the surface of the Erath, its atmosphere, hydrosphere and cryosphere are developed. Map-making databases are created to assess the environmental conditions and forecast development of dangerous natural processes. New methods to carry out environmental and geological due diligence of big economic sites are elaborated. Modeling of natural processes on the basis of geoinformation technologies is carried out; this technology is used to develop technologies and methods of geoecological monitoring.

Scientists explore processes and regularities of interaction of surface, underground and soil waters, model the on-land hydrological cycle and its reaction on the environmental changes; develop water management theory methods and carry out water control operations to ensure continuous water supply to the Russian regions; develop new forecasting methods and substantiate monitoring structure for catastrophic floods and

high water seasons on the Russian rivers, assess risks of their occurrence, socio-economic and ecological consequences; study mechanisms, monitor and forecast a complex effect of climatic and anthropogenic factors on the processes associated with water quality, structure of water ecosystems and public health; develop theoretical fundamentals of an integrated monitoring of water bodies using data of aerospace measurements.

Among other interests of the present-day geography are dynamics of the cryolithozone in the littoral and shelf zones of the Artie seas to evaluate its state and forecast occurrence of dangerous cryogenic processes in the permafrost. Scientists research conditions of the southern margin of the Russian cryolithozone, including mountainous areas, in terms of global climatic changes and constant technogenic development. Geocryological history in cryogenic and paleocryogenic areas is reconstructed; physical and chemical fundamentals of interaction between relic gas hydrate horizons and permafrost formations on land and in the shallow shelf areas are studied, which makes it possible to forecast cryogenesis.

Cryosphere is studied as an important element of the Earth's evolution and its influence on the climate formation. Scientists research reaction of the snow cover and glaciers on the territory of Eurasia for the last century, forecast conditions of the cryosphere in the 21st century, including intensification of natural processes. Extent and regimes of the snow cover, snow avalanches, mud streams and water-snow flows as well as factors of their formation are under scientific focus. Specialists create models of formation of seismic avalanches and research cryogenesis as a factor maintaining stable conditions of natural objects and engineering facilities.

Modern geography studies effects of different types of environmental management on the natural resource and ecological potential of the territory; identifies and substantiates indicators of stability of different Eurasia landscapes preventing technogenic exposure and climatic changes. Changes in the state of disturbed lands in different natural areas are studied and recultivation methods are developed, including reconditioning of natural landscapes. Specialists develop ecological hazard assessment methods to be used on the regional and local levels for a stable development of Russia. Ecological and geographical framework of sustainable development of the country and the planet is developed, scientists are focused on the geographical and geoinformation support of the Russian Federation during transition to the sustainable development in terms of climatic changes to be used in the territorial development and strategic planning.

New biological zoning of the Russian Federation is now developed to increase the efficiency and representation of territorial protection of the nature, creation of natural heritage, landscapes and biota. Transformation trends of the biota in the zonal landscapes of the Russian Federation are identified; forecasts of biota development in view of invasion of alien species of plants and animals are made taking into account different climatic and socio-economic development scenarios of Russia and the planet. Evolution of soil systems as well as changes in the components of heat, water and carbon balance in different on-land ecosystems triggered by anthropogenic influence and global climatic changes are studied. Specialists assess ecological, geographical and environmental consequences of Russia's membership in the World Trade Organization.

Impact of urban development on the environment and criteria of assessment of ecological situation in small and medium size towns are studied. A long-term strategy of sustainable and balanced development of the natural and climatic potential of Russia, a concept of creation of a single network of natural objects under special protection and formation of the landscape and ecological framework of the Russian regions are developed. A strategy of territorial development and scientific fundamentals of the regional policy of the Russian Federation in terms of depopulation and reduction of territories has been proposed; foreign experience, including studies carried out in countries with transitional economy, is under consideration by national scientists.

The above-listed research works are conducted by large scientific teams, which means that the frontline of geography as a science is still vast and will hardly shrink in the future.