The body of water outside the land is called oceans. The waters of the World Ocean occupy about 70.8% of the surface area of ​​​​our planet (361 million km 2) and play an extremely important role in the development of the geographical envelope.

The world ocean contains 96.5% of the waters of the hydrosphere. The volume of its waters is 1,336 million km 3. The average depth is 3711 m, the maximum is 11022 m. The prevailing depths are from 3000 to 6000 m. They account for 78.9% of the area.

The temperature of the water surface is from 0°C and below in the polar latitudes to +32°C in the tropics (Red Sea). To the bottom layers, it decreases to +1°C and below. The average salinity is about 35 ‰, the maximum is 42 ‰ (Red Sea).

The oceans are divided into oceans, seas, bays, straits.

Borders oceans not always and not everywhere they pass along the coasts of the continents, they are often carried out very conditionally. Each ocean has a complex of inherent qualities only to it. Each of them is characterized by its own system of currents, a system of tides, a specific distribution of salinity, its own temperature and ice regime, its own circulation with air currents, its own character of depths and dominant bottom sediments. Allocate Pacific (Great), Atlantic, Indian and Arctic oceans. Sometimes the Southern Ocean is also distinguished.

Sea - a significant area of ​​the ocean, more or less isolated from it by land or underwater rises and differing in its natural conditions (depth, bottom topography, temperature, salinity, waves, currents, tides, organic life).

Depending on the nature of the contact between continents and oceans Seas are divided into the following three types:

1.Mediterranean seas: are located between two continents or are located in the fault belts of the earth's crust; they are characterized by a strong indentation of the coastline, a sharp drop in depths, seismicity and volcanism (Sargasso Sea, Red Sea, Mediterranean Sea, Sea of ​​​​Marmara, etc.).

2. Inland seas: deeply protrude into land, located inside the continents, between islands or continents or within the archipelago, significantly separated from the ocean, characterized by shallow depths (White Sea, Baltic Sea, Hudson Sea, etc.).

3. Marginal seas: located on the outskirts of the continents and large islands, on continental shallows and slopes. They are wide open towards the ocean (the Norwegian Sea, the Kara Sea, the Sea of ​​Okhotsk, the Sea of ​​Japan, the Yellow Sea, etc.).

The geographical position of the sea largely determines its hydrological regime. Inland seas are weakly connected to the ocean, so the salinity of their water, currents and tides differ markedly from those of the ocean. The regime of the marginal seas is essentially oceanic. Most of the seas are northern continents especially off the coast of Eurasia.

gulf - a part of the ocean or sea that protrudes into the land, but has free water exchange with the rest of the water area, differs slightly from it in terms of natural features and regime. The difference between the sea and the bay is not always perceptible. In principle, the bay is smaller than the sea; every sea forms bays, but the opposite does not happen. Historically, in the Old World, even small water areas, such as Azov and Marmara, are called seas, and in America and Australia, where names were given by European discoverers, even large seas are called bays - Hudson, Mexican. Sometimes the same water areas are called one sea, the other - a bay (Arabian Sea, Bay of Bengal).

Depending on the origin, coast structure, shape and size, bays are called bays, fjords, estuaries, lagoons:

Bays (harbours)- bays of small size, protected from waves and winds by capes protruding into the sea. They are convenient for mooring ships (Novorossiysk, Sevastopol - the Black Sea, the Golden Horn - the Sea of ​​Japan, etc.).

fjords- narrow, deep, long bays with protruding, steep, rocky shores and a trough-shaped profile, often separated from the sea by underwater rapids. The length of some can reach more than 200 km, the depth - more than 1000 m. Their origin is associated with faults and erosional activity of Quaternary glaciers (the coast of Norway, Greenland, Chile).

Estuaries- shallow, deeply protruding bays with spits and embankments. They are formed in the widened mouths of rivers when the coastal land sinks (the Dnieper and Dniester estuaries in the Black Sea).

lagoons- Shallow bays with salty or brackish water stretched along the coast, separated from the sea by spits, or connected to the sea by a narrow strait (well developed on the coast of the Gulf of Mexico).

Lips- shallow bays into which large rivers usually flow. Here, the water is highly desalinated, differs sharply in color from the water of the adjacent sea area and has yellowish and brownish hues (Penzhina Bay).

Straits - relatively narrow water spaces connecting separate parts of the World Ocean and separating land areas. According to the nature of water exchange, they are divided into: flowing– currents are directed along the entire cross section in one direction; exchange The waters move in opposite directions. In them, water exchange can occur vertically (Bosphorus) or horizontally (Laperouse, Devisov).

structure The world ocean is called its structure - vertical stratification of waters, horizontal (geographical) zonality, the nature of water masses and ocean fronts.

In a vertical section, the water column breaks up into large layers, similar to the layers of the atmosphere. The following four spheres (layers) are distinguished:

Upper sphere formed by direct exchange of energy and matter with the troposphere. It covers a layer of 200–300 m thick. This upper sphere is characterized by intense mixing, light penetration and significant temperature fluctuations.

Intermediate sphere extends to depths of 1500–2000 m; its waters are formed from surface waters when they sink. At the same time, they are cooled and compacted, and then mixed in horizontal directions, mainly with a zonal component. They stand out in the polar regions with elevated temperatures, in temperate latitudes and tropical regions with low or high salinity. Horizontal transfers of water masses predominate.

Deep Sphere does not reach the bottom by about 1000 m. This sphere is characterized by a certain uniformity. Its thickness is about 2000 m and it concentrates more than 50% of all the water of the World Ocean.

bottom sphere occupies the lowest layer of the ocean and extends to a distance of about 1000 m from the bottom. The waters of this sphere are formed in cold zones, in the Arctic and Antarctic and move over vast expanses through deep basins and trenches, are distinguished by the lowest temperatures and highest density. They perceive heat from the bowels of the Earth and interact with the ocean floor. Therefore, during their movement, they are significantly transformed.

A water mass is a relatively large volume of water that forms in a certain area of ​​the World Ocean and has almost constant physical (temperature, light), chemical (gases) and biological (plankton) properties for a long time. One mass is separated from another by an ocean front.

The following types of water masses are distinguished:

1. Equatorial water masses are characterized by the highest temperature in the open ocean, low salinity (up to 34–32 ‰), minimum density, high content of oxygen and phosphates.

2. Tropical and subtropical water masses are created in the areas of tropical atmospheric anticyclones and are characterized by high salinity (up to 37 ‰ and more) and high transparency, poverty of nutrient salts and plankton. Ecologically, they are oceanic deserts.

3. Moderate water masses are located in temperate latitudes and are characterized by great variability of properties, as in geographical latitudes as well as the seasons of the year. Moderate water masses are characterized by an intense exchange of heat and moisture with the atmosphere.

4. The polar water masses of the Arctic and Antarctic are characterized by the lowest temperature, highest density, and high oxygen content. The waters of the Antarctic sink intensively into the near-bottom sphere and supply it with oxygen.

The waters of the World Ocean are in continuous movement and mixing. Unrest – oscillatory movements water, currents- progressive. main reason unrest (waves) on the surface - wind at a speed of more than 1 m / s. The excitement caused by the wind fades with depth. Deeper than 200 m, even strong waves are already imperceptible. At a wind speed of approximately 0.25 m / s, ripples. When the wind increases, the water experiences not only friction, but also air blows. Waves grow in height and length, increasing the period of oscillation and speed. The ripples turn into gravitational waves. The magnitude of the waves depends on the wind speed and acceleration. The maximum height in temperate latitudes (up to 20 - 30 meters). The least excitement is in the equatorial zone, the frequency of calm is 20 - 33%.

Seismic waves are generated by underwater earthquakes and volcanic eruptions. tsunami. The length of these waves is 200 - 300 meters, the speed is 700 - 800 km / h. seiches(standing waves) occur as a result of sudden changes in pressure over the water surface. Amplitude 1 - 1.5 meters. Characteristic of closed seas and bays.

sea ​​currents- these are horizontal movements of water in the form of wide streams. Surface currents are caused by wind, while deep currents are caused by different water densities. Warm currents (Gulf Stream, North Atlantic) are directed from lower latitudes towards wider ones, cold ones (Labrodor, Peruvian) - vice versa. In tropical latitudes near the western coasts of the continents, the trade winds drive warm water and carry it westward. In its place, cold water rises from the depths. 5 cold currents are formed: Canary, California, Peruvian, West Australian and Benguela. In the southern hemisphere, the cold streams of the current of the West Winds pour into them. Warm waters are formed by moving parallel trade wind currents: North and South. In the Indian Ocean in the northern hemisphere - monsoon. At the eastern coasts of the continents, they are divided into parts, deviate to the north and south and go along the continents: at 40 - 50º N.S. under the influence of westerly winds, the currents deviate to the east and form warm currents.

Tidal movements ocean waters arise under the influence of the forces of attraction of the moon and the sun. The highest tides are observed in the Bay of Fundy (18 m). There are semi-diurnal, diurnal and mixed tides.

Also, the water dynamics is characterized by vertical mixing: in convergence zones - water subsidence, in divergence zones - upwelling.

The bottom of the oceans and seas is covered with sedimentary deposits called marine sediments , soils and silts. According to the mechanical composition, udon deposits are classified into: coarse-grained sedimentary rocks or psephites(blocks, boulders, pebbles, gravel), sandy rocks or psummits(sands coarse, medium, fine), silty rocks or silts(0.1 - 0.01 mm) and clayey rocks or pellets.

According to the material composition, bottom sediments are divided into weakly calcareous (lime content 10–30%), calcareous (30–50%), highly calcareous (more than 50%), weakly siliceous (silicon content 10–30%), siliceous (30–50%) and strongly siliceous (more than 50%) deposits. According to the genesis, terrigenous, biogenic, volcanogenic, polygenic and authigenic deposits are distinguished.

Terrigenous precipitation is brought from land by rivers, wind, glaciers, surf, tides and tides in the form of rock destruction products. Near the coast, they are represented by boulders, further by pebbles, sands, and finally, silts and clays. They cover approximately 25% of the ocean floor, occur mainly on the shelf and continental slope. A special variety of terrigenous deposits are iceberg deposits, which are characterized by a low content of lime, organic carbon, poor sorting, and a diverse granulometric composition. They are formed from sedimentary material that falls to the ocean floor when icebergs melt. They are most characteristic of the Antarctic waters of the World Ocean. There are also terrigenous deposits of the Arctic Ocean, formed from sedimentary material brought by rivers, icebergs, river ice. Turbidites, sediments of turbidity flows, also have a mostly terrigenous composition. They are typical of the continental slope and continental foot.

Biogenic precipitation are formed directly in the oceans and seas as a result of the death of various marine organisms, mainly planktonic, and the precipitation of their insoluble residues. According to their material composition, biogenic deposits are divided into siliceous and calcareous.

Siliceous sediments consist of the remains of diatoms, radiolarians and flint sponges. Diatom sediments are widespread in the southern parts of the Pacific, Indian and Atlantic oceans in the form of a continuous belt around Antarctica; in the northern part of the Pacific Ocean, in the Bering and Okhotsk seas, but here they contain a high admixture of terrigenous material. Separate patches of diatom oozes have been found at great depths (more than 5000 m) in the tropical zones of the Pacific Ocean. Diatom-radiolarian deposits are most common in the tropical latitudes of the Pacific and Indian oceans, flint-sponge deposits are found on the shelf of Antarctica, the Sea of ​​Okhotsk.

lime deposits, like siliceous, are divided into a number of types. The most widely developed are foraminiferal-coccolithic and foraminiferal oozes, which are distributed mainly in the tropical and subtropical parts of the oceans, especially in the Atlantic. A typical foraminiferal silt contains up to 99% lime. The shells of planktonic foraminifers, as well as coccolithophorids, shells of planktonic calcareous algae, constitute a significant part of such oozes. With a significant admixture in the bottom sediments of shells of planktonic pteropod mollusks, pteropod-foraminiferal deposits are formed. Large areas of them are found in the equatorial Atlantic, as well as in the Mediterranean, Caribbean Seas, in the Bahamas, in the Western Pacific Ocean and other areas of the World Ocean.

Coral-algae deposits occupy the equatorial and tropical shallow waters of the western part of the Pacific Ocean, cover the bottom in the north of the Indian Ocean, in the Red and Caribbean Seas, shelly carbonate deposits - coastal zones of the seas of temperate and subtropical zones.

Pyroclastic or volcanogenic sediments are formed as a result of the products of volcanic eruptions entering the World Ocean. Usually these are tuffs or tuff breccias, less often - unconsolidated sands, silts, less often sediments of deep, highly saline and high-temperature underwater sources. So, at their outlets in the Red Sea, highly ferruginous sediments with a high content of lead and other non-ferrous metals are formed.

To polygenic sediments one type of bottom sediments is referred to as deep-water red clay, a sediment of pelitic composition of brown or brown-red color. This color is due to the high content of iron and manganese oxides. Deep-water red clays are common in the abyssal basins of the oceans at depths of more than 4500 m. They occupy the most significant areas in the Pacific Ocean.

authigenic or chemogenic sediments are formed as a result of chemical or biochemical precipitation of certain salts from sea water. These include oolitic deposits, glauconite sands and silts, and ferromanganese nodules.

Oolites- the smallest balls of lime, found in the warm waters of the Caspian and Aral Seas, the Persian Gulf, in the Bahamas.

Glauconite sands and silts– precipitation different composition with a noticeable admixture of glauconite. They are most widespread on the shelf and continental slope off the Atlantic coast of the USA, Portugal, Argentina, on the underwater margin of Africa, off the southern coast of Australia and in some other areas.

ferromanganese nodules- concretions of iron and manganese hydroxides with an admixture of other compounds, primarily cobalt, copper, nickel. They occur as inclusions in deep-water red clays and in places, especially in the Pacific Ocean, form large accumulations.

More than a third of the entire area of ​​the ocean floor is occupied by deep-water red clay, and approximately the same distribution area is covered by foraminiferal sediments. The rate of accumulation of sediments is determined by the thickness of the layer of sediments deposited on the bottom over 1000 years (in some areas 0.1–0.3 mm per thousand years, in estuaries, transition zones and gutters - hundreds of millimeters per thousand years).

In the distribution of bottom sediments in the World Ocean, the law of latitudinal geographical zonality is clearly manifested. So, in the tropical and temperate zones, the ocean floor to a depth of 4500–5000 m is covered with biogenic calcareous deposits, deeper - with red clays. The subpolar belts are occupied by siliceous biogenic material, while the polar belts are occupied by iceberg deposits. Vertical zoning finds expression in the replacement of carbonate sediments at great depths by red clays.

Layer cake in the ocean

In 1965, the American scientist Henry Stommel and the Soviet scientist Konstantin Fedorov jointly tested a new American instrument for measuring the temperature and salinity of ocean waters. The work was carried out in the Pacific Ocean between the islands of Mindanao (Philippines) and Timor. The device was lowered on a cable into the depths of the waters.

One day, the researchers found an unusual recording of measurements on the instrument's recorder. At a depth of 135 m, where the mixed layer of the ocean ended, the temperature should, according to existing ideas, begin to decrease uniformly with depth. And the device registered its increase by 0.5 °C. A layer of water with such an elevated temperature had a thickness of about 10 m. Then the temperature began to decrease.

Here is what Dr. technical sciences N. V. Vershinsky, head of the laboratory of marine measuring instruments Institute of Oceanology of the Academy of Sciences of the USSR: “To understand the surprise of researchers, it must be said that in any oceanography course of those years, one could read something like the following about the vertical distribution of temperature in the ocean. Initially, the upper mixed layer extends from the surface to the depth. In this layer, the water temperature remains practically unchanged. The thickness of the mixed layer is usually 60 - 100 m. Wind, waves, turbulence, current all the time mix the water in the surface layer, due to which its temperature becomes approximately the same. But the possibilities of mixing forces are limited, at some depth their action stops. With further immersion, the temperature of the water decreases sharply. Leap!

This second layer is called the jump layer. Usually it is small and is only 10–20 m. Over these few meters, the water temperature drops by several degrees. The temperature gradient in the shock layer is usually a few tenths of a degree per meter. This layer is an amazing phenomenon that has no analogue in the atmosphere. It plays a large role in the physics and biology of the sea, as well as in human activities related to the sea. Due to the large density gradient in the jump layer, various suspended particles, planktonic organisms and fish fry are collected. The submarine can lie in it, as on the ground. Therefore, sometimes it is called a layer of "liquid soil".

The jump layer is a kind of screen: the signals of echo sounders and sonars do not pass through it well. By the way, he does not always stay in one place. The layer moves up or down and sometimes with quite high speed. Below the shock layer, there is a layer of the main thermocline. In this third layer, the water temperature continues to decrease, but not as fast as in the jump layer, the temperature gradient here is a few hundredths of a degree per meter ...

Over the course of two days, the researchers repeated their measurements several times. The results were similar. The records irrefutably testified to the presence in the ocean of thin layers of water ranging from 2 to 20 km in length, the temperature and salinity of which differed sharply from the neighboring ones. The thickness of the layers is from 2 to 40 m. The ocean in this area resembled a layer cake.”

In 1969, the English scientist Woods found elements of microstructure in the Mediterranean Sea near the island of Malta. He first used a two-meter rail for measurements, on which he fixed a dozen semiconductor temperature sensors. Woods then designed a self-contained falling probe that helped to clearly capture the layered structure of water temperature and salinity fields.

And in 1971, the layered structure was first discovered in the Timor Sea by Soviet scientists on the R/V Dmitry Mendeleev. Then, during the voyage of the vessel in the Indian Ocean, scientists found elements of such a microstructure in many areas.

Thus, as is often the case in science, the use of new instruments to measure previously repeatedly measured physical parameters has led to new sensational discoveries.

Previously, the temperature of the deep layers of the ocean was measured with mercury thermometers at separate points at different depths. From the same points, water samples were taken from the depth with the help of bottle meters for subsequent determination of its salinity in the ship's laboratory. Then, based on the results of measurements at individual points, oceanologists built smooth curves for graphs of changes in water parameters with depth below the shock layer.

Now new instruments - fast-response probes with semiconductor sensors - have made it possible to measure the continuous dependence of water temperature and salinity on the depth of probe immersion. Their use made it possible to catch very small changes in the parameters of water masses when the probe moved vertically within tens of centimeters and record their changes over time in fractions of seconds.

It turned out that everywhere in the ocean, the entire water mass from the surface to great depths is divided into thin homogeneous layers. The difference in temperature between adjacent horizontal layers was several tenths of a degree. The layers themselves have a thickness from tens of centimeters to tens of meters. The most striking thing was that during the transition from layer to layer, the temperature of the water, its salinity and density changed sharply, abruptly, and the layers themselves stably exist sometimes for several minutes, and sometimes for several hours and even days. And in the horizontal direction, such layers with uniform parameters extend over a distance of up to tens of kilometers.

The first messages about the discovery of the fine structure of the ocean were not accepted by all oceanologists calmly and favorably. Many scientists took the measurement results as an accident and a misunderstanding.

Indeed, there was something to be surprised. After all, water in all ages has been a symbol of mobility, variability, fluidity. Especially the water in the ocean, where its structure is extremely variable, waves, surface and underwater currents mix the water masses all the time.

Why is such a stable layering preserved? There is no single answer to this question yet. One thing is clear: all these measurements are not a play of chance, not a chimera - something important has been discovered that plays a significant role in the dynamics of the ocean. According to the doctor of geographical sciences A. A. Aksenov, the reasons for this phenomenon are not entirely clear. So far, they explain it this way: for one reason or another, numerous fairly clear boundaries appear in the water column, separating layers with different densities. At the boundary of two layers of different density, internal waves very easily arise, which mix the water. With the destruction of internal waves, new homogeneous layers arise and the boundaries of the layers are formed at other depths. This process is repeated many times, the depth and thickness of layers with sharp boundaries change, but the general nature of the water column remains unchanged.

The revealing of the thin-layer structure continued. Soviet scientists A. S. Monin, K. N. Fedorov, V. P. Shvetsov discovered that deep currents in the open ocean also have a layered structure. The current remains constant within a layer with a thickness of 10 cm to 10 m, then its speed changes abruptly when moving to an adjacent layer, etc. And then scientists discovered a “layered pie”.

A significant contribution to the study of the fine structure of the ocean was made by our oceanologists, using the scientific equipment of new medium-tonnage specialized R/Vs with a displacement of 2600 tons, built in Finland.

This is the R/V Akademik Boris Petrov, owned by the Institute of Geochemistry and Analytical Chemistry named after V.I. V. I. Vernadsky of the Academy of Sciences of the USSR, “Academician Nikolai Strakhov”, working according to the plans of the Geological Institute of the Academy of Sciences of the USSR, and belonging to the Far Eastern Branch of the Academy of Sciences of the USSR “Academician M.A. Lavrentiev”, “Academician Oparin”.

These ships were named after prominent Soviet scientists. Hero of Socialist Labor Academician Boris Nikolaevich Petrov (1913-1980) was a prominent scientist in the field of control problems, a talented organizer of space science and international cooperation in this field.

The appearance of the name of academician Nikolai Mikhailovich Strakhov (1900 - .1978) on board the ship of science is also natural. The outstanding Soviet geologist made a major contribution to the study of sedimentary rocks at the bottom of the oceans and seas.

The Soviet mathematician and mechanic Academician Mikhail Alekseevich Lavrentiev (1900–1979) became widely known as a major organizer of science in Siberia and the east of the USSR. It was he who stood at the origins of the creation of the famous Akademgorodok in Novosibirsk. In recent decades, research at the institutes of the Siberian Branch of the USSR Academy of Sciences has acquired such a scale that it is now impossible to imagine the overall picture in almost any field of science without taking into account the work of Siberian scientists.

Of the four R/Vs of this series, three (except for the R/V Akademik Oparin) were built for hydrophysical studies of the water masses of the oceans and seas, studies of the ocean floor and atmospheric layers adjacent to the ocean surface. Based on these tasks, the research complex installed on the ships was designed.

Important integral part of this complex are submersible probes. Hydrological and hydrochemical laboratories, as well as the so-called "wet laboratory" are located in the forward part of the main deck of the ships of this series. The scientific equipment placed in them includes recording units of submersible probes with electrical conductivity, temperature and density sensors. Moreover, the design of the hydrosonde provides for the presence of a set of bottles on it for taking water samples from different horizons.

These vessels are equipped with not only deep-sea narrow-beam research echo sounders, but also multi-beam ones.

As the well-known researcher of the World Ocean, doctor of geographical sciences Gleb Borisovich Udintsev, said, the appearance of these devices - multibeam echo sounders - should be assessed as a revolution in the study of the ocean floor. After all, for many years our ships were equipped with echo sounders that measured depths using a single beam directed from the ship down the vertical. This made it possible to obtain a two-dimensional image of the relief of the ocean floor, its profile along the route of the vessel. Until now, using a large amount of data collected with the help of single-beam echo sounders, maps of the relief of the bottom of the seas and oceans have been compiled.

However, the construction of maps according to bottom profiles, between which it was necessary to draw lines of equal depths - isobaths, depended on the ability of a cartographer-geomorphologist or hydrographer to create a spatial three-dimensional image based on the synthesis of all available geological and geophysical information. It is clear that at the same time, maps of the relief of the ocean floor, which then served as the basis for all other geological and geophysical maps, contained a lot of subjectivity, which was especially evident when they were used to develop hypotheses for the origin of the bottom of the seas and oceans.

The situation has changed significantly with the advent of multibeam echo sounders. They allow you to receive sound signals reflected by the bottom, sent by the echo sounder, in the form of a fan of rays; covering a strip of the bottom surface with a width equal to two ocean depths at the measurement point (up to several kilometers). This not only greatly increases the productivity of research, but, which is especially important for marine geology, it is possible with the help of electronic computing technology to immediately present a three-dimensional image of the relief on the display, as well as graphically. Thus, multibeam echo sounders make it possible to obtain detailed bathymetric maps with a continuous areal coverage of the bottom by instrumental surveys, reducing the proportion of subjective ideas to a minimum.

The very first voyages of Soviet R/Vs equipped with multibeam echo sounders immediately showed the advantages of the new instruments. Their importance became clear not only for performing fundamental work on mapping the bottom of the oceans, but also as a means of actively managing research work as instruments of a kind of acoustic navigation. This made it possible to actively and with minimal time to select locations for geological and geophysical stations, to control the movement of instruments towed above the seabed or along the seabed, to search for seafloor morphological objects, for example, minimum depths above the tops of seamounts, etc.

Particularly effective in realizing the capabilities of a multibeam echo sounder was the cruise of the R/V Akademik Nikolai Strakhov, conducted from April 1 to August 5, 1988 in the equatorial Atlantic.

The studies were carried out on a full range of geological and geophysical works, but the main thing was multibeam echo sounding. For research, the equatorial section of the Mid-Atlantic Ridge in the area of ​​about. Sao Paulo. This little-studied region stood out for its unusualness in comparison with other parts of the ridge: the igneous and sedimentary rocks discovered here unexpectedly turned out to be unusually ancient. It was necessary to find out whether this section of the ridge differs from others in terms of other characteristics, and, above all, in relief. But to solve this problem, it was necessary to have an extremely detailed picture of the underwater relief.

Such a task was set before the expedition. For four months, studies were conducted with intervals between tacks of no more than 5 miles. They covered a vast area of ​​the ocean up to 700 miles wide from east to west and up to 200 miles from north to south. As a result of the studies performed, it became obvious that the equatorial segment of the Mid-Atlantic Ridge, enclosed between the 4° faults in the north and about. Sao Paulo in the south really has an anomalous structure. Typical for the rest of the ridge (to the north and south of the studied area), the structure of the relief, the absence of a thick sedimentary cover and characteristics magnetic field The rocks here turned out to be characteristic only of the narrow axial part of the segment no more than 60–80 miles wide, which was called the Peter and Paul Range.

And what was previously considered the slopes of the ridge turned out to be vast plateaus with a completely different nature of the relief and magnetic field, with a powerful sedimentary cover. So, apparently, the origin of the relief and the geological structure of the plateau are completely different from those of the Peter and Paul Range.

The significance of the results obtained may be very important for the development general ideas on the geology of the bottom of the Atlantic Ocean. However, there is much to be thought through and tested. And this requires new expeditions, new research.

Of particular note is the equipment for the study of water masses installed on the R/V “Arnold Veimer” with a displacement of 2140 tons. This specialized R/V was built by Finnish shipbuilders for the Academy of Sciences of the ESSR in 1984 and named after the prominent statesman and scientist of the ESSR, President of the Academy of Sciences of the ESSR in 1959–1973 gg. Arnold Weimer.

Among the ship's laboratories there are three marine physics (hydrochemical, hydrobiological, marine optics), a computer center and a number of others. For carrying out hydrophysical studies, the ship has a set of current measuring instruments. The signals from them are received by the hydrophone receiver installed on the ship and transmitted to the data recording and processing system, and also recorded on magnetic tape.

For the same purpose, free-floating current detectors by Bentos are used to record the values ​​of the current parameters, the signals from which are also received by the ship's receiver.

The vessel has an automated system for sampling from various horizons and measuring hydrophysical and hydrochemical parameters using research probes with acoustic current meters, sensors for dissolved oxygen content, hydrogen ion concentration (pH) and electrical conductivity.

The hydrochemical laboratory is equipped with high-precision equipment, which makes it possible to analyze samples of sea water and bottom sediments for the content of trace elements. Complex and precise instruments are designed for this purpose: spectrophotometers of various systems (including atomic absorption), a fluorescent liquid chromatograph, a polarographic analyzer, two automatic chemical analyzers, etc.

At the hydrochemical laboratory there is a through shaft in a housing measuring 600X600 mm. From it it is possible to take sea water from under the ship and lower the instruments into the water under adverse weather conditions that do not allow the use of deck devices for these purposes.

The optical laboratory has two fluorometers, a dual beam spectrophotometer, an optical multichannel analyzer and a programmable multichannel analyzer. Such equipment allows scientists to conduct a wide range of studies related to the study of the optical properties of sea water.

In the hydrobiological laboratory, in addition to standard microscopes, there is an Olympus plankton microscope, special equipment for conducting research using radioactive isotopes: scintillation counter and particle analyzer.

Of particular interest is the ship's automated system for recording and processing the collected scientific data. The computer center hosts a Hungarian-made mini-computer. This computer is a dual-processor system, that is, the solution of problems and the processing of experimental data is carried out in the computer in parallel using two programs.

For automated recording of the collected experimental data coming from numerous instruments and devices, two cable systems are installed on the ship. The first is a radial cable network for transmitting data from laboratories and measurement sites to the main switchboard.

On the console, you can connect the measurement lines to any contact and output the incoming signals to any ship computer. Distribution boxes of this line are installed in all laboratories and at work sites near the winches. The second cable network is a backup for connecting new instruments and devices that will be installed on the ship in the future.

An excellent system, but this relatively powerful and extensive system for collecting and processing data with the help of a computer is so successfully placed on a small medium-tonnage R/V.

R/V "Arnold Veimer" is exemplary for a medium-tonnage R/V in terms of the composition of scientific equipment and the possibilities of conducting multifaceted studies. During its construction and equipping, the composition of scientific equipment was carefully thought out by scientists of the Academy of Sciences of the Estonian SSR, which significantly increased the efficiency of research work after the vessel was put into operation.