Gravimetry is a section of the science of measuring quantities characterizing the Earth's gravitational field and using them to determine the shape of the Earth, study its general internal structure, the geological structure of its upper parts, solve some navigation problems, etc.
In gravimetry, the Earth's gravitational field is usually set by the field of gravity (or the numerically equal acceleration of gravity), which is the result of two main forces: the force of attraction (gravity) of the Earth and the centrifugal force caused by its daily rotation. Centrifugal force directed away from the axis of rotation reduces the force of gravity, and to the greatest extent at the equator. The decrease in gravity from the poles to the equator is also due to the compression of the Earth.
The force of gravity, that is, the force acting on a unit mass in the vicinity of the Earth (or another planet), consists of the forces of gravity and the forces of inertia (centrifugal force):
where G is the gravitational constant, mu is the unit mass, dm is the mass element, R are the radius vectors of the measurement point, r is the radius vector of the mass element, w is the angular velocity of the Earth's rotation; the integral is taken over all masses.
The potential of gravity, respectively, is determined by the ratio:
where is the latitude of the measurement point.
Gravimetry includes the theory of leveling heights, processing of astronomical and geodetic networks in connection with variations in the Earth's gravitational field.
The unit of measurement in gravimetry is Gal (1 cm / s2), named after the Italian scientist Galileo Galilei.
Determinations of the force of gravity are made by the relative method, by measuring with the help of gravimeters and pendulum devices the difference in the force of gravity in the studied and reference points. The network of gravimetric reference points throughout the Earth is ultimately connected with the point in Potsdam (Germany), where the absolute value of the acceleration of gravity was determined by revolving pendulums at the beginning of the 20th century (981,274 mgl; see Gal). Absolute definitions of gravity are difficult and less accurate than relative measurements. New absolute measurements made at more than 10 points on the Earth show that the reduced value of the acceleration of gravity in Potsdam is exceeded, apparently, by 13-14 mgl. Upon completion of these works, the transition to a new gravimetric system will be carried out. However, in many problems of gravimetry, this error is not significant, since to solve them, not the absolute values \u200b\u200bthemselves are used, but their differences. The absolute value of the force of gravity is most accurately determined from experiments with the free fall of bodies in a vacuum chamber. The relative determinations of the force of gravity are made by pendulum instruments with an accuracy of several hundredths of a millimeter. Gravimeters provide slightly higher measurement accuracy than pendulum instruments, are portable and easy to use. There is special gravimetric equipment for measuring gravity from moving objects (submarines and surface ships, aircraft). The instruments continuously record changes in the acceleration of gravity along the path of a ship or aircraft. Such measurements are associated with the difficulty of excluding from the instrument readings the influence of disturbing accelerations and tilts of the instrument base caused by rolling. There are special gravimeters for measurements at the bottom of shallow water basins, in boreholes. The second derivatives of the gravity potential are measured using gravity variometers.
The main range of problems of gravimetry is solved by studying the stationary spatial gravitational field. To study the elastic properties of the Earth, continuous registration of variations in the force of gravity over time is performed. Due to the fact that the Earth is inhomogeneous in density and has an irregular shape, its external gravitational field is characterized by a complex structure. To solve various problems, it is convenient to consider the gravitational field consisting of two parts: the main one - called normal, which varies with the latitude of the place according to a simple law, and anomalous - small in magnitude, but complex in distribution, due to inhomogeneities in the density of rocks in the upper layers of the Earth. The normal gravitational field corresponds to some idealized model of the Earth, simple in shape and internal structure (an ellipsoid or a spheroid close to it). The difference between the observed gravity and normal gravity, calculated by one or another formula for the distribution of normal gravity and reduced by appropriate corrections to the accepted level of heights, is called the gravity anomaly. If this reduction takes into account only the normal vertical gravity gradient of 3086 evesh (i.e., assuming that there are no masses between the observation point and the reference level), then the anomalies obtained in this way are called free air anomalies. The anomalies calculated in this way are most often used when studying the figure of the Earth. If the reduction also takes into account the attraction of a layer of masses considered to be homogeneous between the observation and reduction levels, then anomalies are obtained, called Bouguer anomalies. They reflect the heterogeneity in the density of the upper parts of the Earth and are used in solving geological exploration problems. In gravimetry, isostatic anomalies are also considered, which in a special way take into account the effect of masses between the earth's surface and the surface level at a depth at which the overlying masses exert the same pressure. In addition to these anomalies, a number of others are calculated (Preya, modified by Bouguer, etc.). Based on gravimetric measurements, gravimetric maps with isolines of gravity anomalies are constructed. Anomalies of the second derivatives of the gravity potential are determined similarly as the difference between the observed value (previously corrected for the terrain) and the normal value. Such anomalies are mainly used for mineral exploration.
In tasks involving the use of gravimetric measurements to study the shape of the Earth, it is usually the search for an ellipsoid that best represents the geometric shape and external gravitational field of the Earth.
Exploration of planet Earth in the solar system: history, description of the surface, spacecraft launch, rotation, orbit, achievements, significant dates.
This is about the home planet, so let's see how the exploration of the Earth went. Most of the earth's surface had been studied by the beginning of the 20th century, including the internal structure and geography. The Arctic and Antarctic remained mysterious. Today, almost all areas have been captured and mapped thanks to photographic mapping and radar. One of the last areas to be explored was the Darien Peninsula, located between the Panama Canal and Colombia. Previously it was difficult to complete the survey due to constant rainfall, dense vegetation and dense cloud cover.
The study of the deep features of the planet has not been conducted for a long time. Before that, they were engaged in the study of surface formations. But after the Second World War, they started geophysical research. For this, special sensors were used. But this way it was possible to consider a limited part of the subsurface layer. It was possible to get only under the upper crust. The maximum well depth is 10 km.
Main goals and achievements in Earth exploration
In exploring the Earth, scientists are driven by scientific curiosity as well as economic benefits. The population is increasing, so the demand for fossils, as well as water and other important materials, is growing. Many underground operations search for:
- oil, coal and natural gas;
- commercial (iron, copper, uranium) and construction (sand, gravel) materials;
- groundwater;
- rocks for engineering planning;
- geothermal reserves for electricity and heating;
- archeology;
There was also a need to create security through tunnels, storage facilities, nuclear reactions and dams. And this leads to the need to be able to predict the strength and timing of an earthquake or the level of subsurface water. Japan and the United States are the most active in earthquakes and volcanoes, because these countries most often suffer such disasters. Wells are periodically drilled for maintenance purposes.
Methodology and toolsearth exploration
You should know what methods of research of planet Earth exist. Geophysics uses magnetism, gravity, reflectivity, elastic or acoustic waves, heat flux, electromagnetism and radioactivity. Most of the measurements are carried out on the surface, but there are satellite and underground ones.
It is important to understand what is below. Sometimes it is not possible to extract oil only because of a block with another material. The choice of method is based on physical properties.
Comparative planetology
Astronomer Dmitry Titov on the types of planets in the solar system, the dynamics of atmospheres and the greenhouse effect on Mars and Venus:
Remote sensing
It uses EM radiation from the ground and reflected energy in a variety of spectral ranges obtained by aircraft and satellites. The methods are based on the use of combinations of images. For this, the sections are recorded from different trajectories and three-dimensional models are created. They are also performed at intervals, which allows you to track the change (increase in yield over the season or changes from storm and rainfall).
Radar beams cut through the clouds. Lateral visible radar is sensitive to changes in surface tilt and roughness. An opto-mechanical scanner registers warm IR energy.
The most commonly used technique is Landsat. This information is obtained by multispectral scanners deployed on some American satellites located at an altitude of 900 km. The footage covers an area of \u200b\u200b185 km. Visible, IR, spectral, green and red ranges are used.
In geology, this technique is used to calculate topography, rock outcrops, and lithology. It is also possible to record changes in vegetation, rocks, find groundwater and the distribution of trace elements.
Magnetic methods
Let's not forget that Earth exploration is carried out from space, providing not only a photo of the planet, but also important scientific data. You can calculate the total earth's magnetic field or specific components. The oldest method is the magnetic compass. Now they use magnetic balances and magnetometers. The proton magnetometer calculates the RF voltage, while the optical pump tracks the smallest magnetic fluctuations.
Magnetic surveys are carried out with magnetometers flying on parallel lines with a distance of 2-4 km and at an altitude of 500 m. Ground surveys consider magnetic anomalies that have occurred in the air. They can be placed on special stations or moving ships.
Magnetic effects are formed due to the magnetization created by sedimentary rocks. Rocks are not able to hold magnetism if temperatures exceed 500 ° C, which is the limit for a depth of 40 km. The source should be located deeper and scientists believe that it is the convection currents that generate the field.
Gravity methods
Space exploration of the Earth includes various directions. The gravitational field can be determined through the fall of any object in a vacuum, by calculating the period of the pendulum, or in other ways. Scientists use gravimeters - a weight on a spring that can stretch and compress. They act to the nearest 0.01 milligram.
The differences in gravity are due to the local plane. It takes several minutes to determine the data, but the calculation of position and altitude takes longer. More often than not, the density of sedimentary rocks increases with depth because pressure rises and porosity is lost. When lifts move rocks closer to the surface, they create abnormal weights. Mineral resources also cause negative anomalies, so understanding gravity can indicate the source of oil, as well as the location of caves and other underground cavities.
Seismic refraction techniques
The scientific method for exploring the Earth is based on calculating the time interval between the beginning of a wave and its arrival. A wave can be created by an explosion, a dropped weight, an air bubble, etc. To search for it, a geophone (land) and a hydrophone (water) are used.
Seismic energy arrives at the detector in a variety of ways. At first, while the wave is close to the source, it chooses the shortest paths, but with increasing distance it starts to wag. Two types of waves can pass through the body: P (primary) and S (secondary). The former act as compression waves and move at maximum acceleration. The latter are shear, moving at a low speed and unable to pass through liquids.
The main type of surface type is Rayleigh waves, where a particle moves along an elliptical path in a vertical plane from the source. The horizontal part is the main cause of earthquakes.
Most of the information about the earth's structure is based on the analysis of earthquakes, since they generate several wave modes at once. They all differ in movement components and direction. In engineering studies, fine seismic refraction is used. Sometimes a simple blow with a sledgehammer is enough. They are also used for troubleshooting.
Electrical and EM methods
When prospecting for minerals, methods depend on electrochemical activity, changes in resistivity, and dielectric permittivity effects. The potential itself is based on the oxidation of the upper surface of the metal sulfide minerals.
Resistivity uses the transfer of current from a generator to another source and determines the potential difference. Rock resistivity depends on porosity, salinity and other factors. Clay rocks are endowed with low resistivity. This method can be used to study underwater waters.
Probing accurately calculates how resistivity changes with depth. Currents with a range of 500-5000 Hz penetrate deeply. The frequency helps determine the depth level. Natural currents are induced due to disturbances in the atmosphere or attack of the upper layer by the solar wind. They cover a wide range so you can explore different depths more efficiently.
But electrical methods are not able to penetrate too deeply, therefore, they do not provide complete information about the lower layers. But with their help, you can study metal ores.
Radioactive methods
This method can identify ores or rocks. The most naturally occurring radioactivity comes from uranium, thorium and the radioisotope potassium. The scintillation meter helps detect gamma rays. The main emitter is potassium-40. Sometimes the rock is deliberately irradiated to measure the impact and response.
Geothermal methods
Calculation of the temperature gradient leads to the determination of the heat flow anomaly. The earth is filled with various liquids, the chemical composition and movement of which are determined by sensitive detectors. Trace elements are sometimes associated with hydrocarbons. Geochemical maps help locate industrial waste and contaminated sites.
Excavation and sampling
To identify different fuels, a sample must be obtained. Many wells are created in a rotary fashion where fluid is circulated through the bit for lubrication and cooling. Percussion is sometimes used, where a heavy drill is lowered and raised to cut pieces of rock.
Conclusions about the depths of the earth
The shape was learned in 1742-1743, and the average density and mass were calculated by Henry Cavendish in 1797. Later they found out that the density of rocks on the surface is lower than the average density, which means that the data inside the planet should be higher.
At the end of the 1500s. William Gilbert studied the magnetic field. From that moment on, they learned about the dipole nature and the change in the geomagnetic field. Earthquake waves were observed in the 1900s. The line between the crust and mantle is characterized by a large increase in velocity at the Mohorovich rupture with a depth of 24–40 km. The boundary between the mantle and the core is the Gutenberg rupture (depth - 2800 km). The outer core is liquid because it does not transmit shear waves.
In the 1950s. there was a revolution in the understanding of our planet. Theories of continental drift have moved into plate tectonics, that is, the lithosphere floats on the asthenosphere. The plates shift and new oceanic crust forms. Also, the lithospheres can approach, move away and cut. Many earthquakes occur at subduction sites.
The oceanic crust was discovered through a series of boreholes. In rift areas, material from the mantle wells cools and solidifies. Sediments gradually accumulate and a basalt foundation is created. The crust is thin (5-8 km in thickness) and almost all young (less than 200,000,000 years). But the relics reach an age of 3.8 billion years.
The continental crust is much older and more difficult to form, making it harder to study. In 1975, a team of scientists used seismic techniques to find oil deposits. In the end, they managed to find several low-angle traction sheets under the Appalachian mountains. This was strongly reflected in the theory of the formation of continents.
Lesson summary on the topic "Modern space methods of studying the Earth in the service
goal : familiarization with the possibilities of space methods of studying the Earth and the application of research results in various fields of human activity.
Tasks and:
exploring a way to capture the earth from space
familiarization with the history and current state of the space method, the achievements of domestic and foreign cosmonautics, development prospects
familiarization with space images and master the basics of visual interpretation of space images
Space exploration and space exploration is one of the most important manifestations of the modern scientific and technological revolution. With the conquest of space, mankind has discovered a lot of new and unknown. Now you can study your home - the Earth from a distance. This was the beginning of the cosmic methods of studying the Earth.
Space methods are remote, because the object under study is studied at a distance.Remote sensing - this is obtaining information about an object without entering into direct contact with it.
The information obtained in this way is of great value in science. It turned out that remote space methods have significant advantages over ground-based methods. First of all, the possibility of obtaining an image of the Earth at different scales (from global to local), efficiency, the ability to repeat the study several times. Surveying from space allows you to capture vast spaces with a single glance and at the same time examine various details of the structure of the area, including those that are not noticeable in the surface of the Earth.
In its development, remote sensing (research) has several stages:
In the 18th century, using the simplest camera obscura - an opaque box with a small hole in the center - they took hand-drawn pictures. The shooting was done from a bird's eye view in a hot air balloon. These images were used to compile topographic maps of the area. It was hard, painstaking work.
With the discovery of photography in 1839, things went much faster. For the first time, it became possible to permanently and objectively capture an image. Initially, cameras were placed on simple aircraft (balloons, kites) and even birds. It was an aerial photograph of the area.
The next step towards what we now call remote sensing was associated with the development of aircraft construction. Already at the beginning of the 20th century, aerial photographs were obtained from aircraft. During the First World War, aerial photography was carried out for reconnaissance purposes.
In the 1930s, aerial photography replaced ground surveying and became the main method of mapping. So, by the mid-50s, using aerial photographs, topographic maps of the entire territory of the USSR were compiled.
The most important impetus in the development of the remote sensing method was the conquest of space by man. In the 60s of the 20th century, it became possible to obtain images taken from space. This event served as an impetus for the development of new types of cameras. In the USA and the USSR, new optoelectronic systems are being developed - scanners that perform multispectral imaging of the earth's surface.
In the 1980s, the widespread use of comic photographs in all areas of the study of earth became possible.
At present, many survey satellites from different countries are moving around the Earth, which regularly survey the Earth and deliver thousands of different images of the Earth's surface to the Earth.
To obtain images of varying degrees of detail, satellites are launched at different heights. Allocatethree main high-altitude tiers of their flight :
Top-tier satellites launched at an altitude of 36,000 km, fly over the equator. They are called geostationary because they rotate with the earth and make a complete revolution around the earth in exactly one day. Such satellites seem to hang in the sky above the same point on the earth. The geostationary can survey almost the entire hemisphere of the Earth.
Geostationary satellites include the Russian Electro, the EU satellite Meteosat", American"GOES- W"And"GOES- E ", Japanese"GMS", Indian"Insat". They conduct continuous global "patrols" of the planet, transmitting survey images every half hour via radio channels.
Middle tier satellites whose orbit passes over the poles (therefore they are called polar), fly at an altitude of 600 to 1500 km. To survey the entire earth's surface, they need from one day to 2-3 weeks.
The middle tier satellites include: the Russian satellite "Meteor 1" and "Meteor 2", the American satelliteNOAA, satellites of Russia "Resurs - P", "Resource - O", AmericanLandsat, FrenchSPOT.
Satellites of the lowest tier , flying at an altitude of 200-300 km, conduct a detailed survey of individual sections of the earth's surface located along the flight path.
Space Earth observation systems are subdivided according to their purpose into meteorological, resource, oceanological, cartographic, navigation, and research.
To obtain images from satellites, various imaging equipment is used. Comparing it with human eyes, we can say that these eyes are different - farsighted and short-sighted, some see in the dark, others through fog and clouds, there are even "color-blind" who see objects in distorted colors.
There are the following groups of such devices:
Photographic apparatus ... The images obtained by such a device are called planned, because in terms of geometric properties, they are close to the area plan. With the help of space cameras, images are obtained only in the visible range.
Satellite scanners ... Unlike cameras, they work in many ranges of the electromagnetic spectrum (they take pictures not only in the visible, but also in the infrared range)
Radars ... If cameras and scanners register solar or their own radiation reflected by objects, then radars themselves "illuminate" the area with a radio beam and receive the reflected radio signal. The radio beam, as it were, probes, probes the surface, sensitively reacting to its roughness. Therefore, even small relief irregularities are visible on the radar images.
As a result of space surveys, a multimillion fund of images has been accumulated. In order to effectively use these images, they are systematized, grouped according to the possibilities of their application. With all the variety of images, they have a number of common characteristics:
Image scale ... Pictures, like maps, vary in scale. They are:
large-scale - 1 cm - 10 m and even larger.
medium-scale
small-scale (1 cm - 100 km)
The scale of the image depends on the height of the survey, the focal length of the apparatus, and the curvature of the earth's surface. The visibility of the image depends on the scale: on large-scale images only individual houses are depicted, on small-scale ones you can see entire continents.
Visibility of images - this is the coverage of the territory with one image.
By visibility, the pictures are divided:global (covering the whole planet)large-regional (cover large regions of the world: Europe, Asia, etc.), regional (region and its part: Belgium, Moscow region); local (depicts a small area of \u200b\u200bthe area: a small town, microdistrict)
Resolution ... The scale of the images is related to their ability to reproduce small objects and individual details. Large-scale images have a resolution of tens of centimeters, i.e. even tree branches can be seen on them. Small-scale images have a resolution of several kilometers, as a result, the observer sees very large areas of the forest or the entire forest zone.
Retrospective. The picture objectively captures the state of the terrain, individual objects and phenomena at the time of shooting. By comparing images from different years, it is possible to assess the dynamics of natural processes: for example, how much the glacier retreated, how ravines grow, and forest areas change.
Stereoscopic. Two images of the same area of \u200b\u200bthe terrain, obtained from different points, form a stereoscopic (i.e., reconstructing a volumetric image) pair of images. Armed with a stereoscope, you can observe from these images not a flat image, but a three-dimensional and very expressive terrain model. This remarkable property of imagery is important for studying the relief of the earth's surface and making maps.
Spectral range .Modern imaging equipment is capable of filming in different ranges of electromagnetic radiation.
On this basis, three groups of images are distinguished:
in the visible range, which is called light
in the thermal infrared range
in the radio range.
The choice of the range determines which objects will be depicted in the pictures. The images in the visible range depict everything that is visible to the human eye; images in the infrared thermal range allow you to determine the surface temperature, and in the radio range - its roughness (i.e. surface roughness). Very often, not one, but a whole series of images in different spectral ranges are obtained simultaneously. Such pictures are calledmultispectral .
With the space-based method of studying the earth, the advent of space imagery and imaging equipment, the possibilities of visual observation have expanded. The human eye perceives only light radiation, and modern devices allow you to "see" the earth's surface in invisible rays: ultraviolet, infrared, in the radio range. And each device "sees" what others do not distinguish.
Satellite information is of great value not only for science. It allows you to solve a number of problems in many sectors of the economy. For example: in agriculture. Thus, satellite information makes it possible to detect areas affected by drought, pests, and man-made emissions. Interesting fact:In the 70s and 80s. The Soviet Union bought large quantities of grain from abroad - in the USA, Canada and other countries. There is no doubt that foreign partners, when determining the price, took into account the types of crops and used satellite information to assess the state of farmland in the USSR.
Space monitoring is actively used in the fight against forest fires. According to the data received from satellites, it is possible to determine the coordinates of the fires, the area and volume of the burned forest, the amount of economic damage. For example: in a photo taken in the Amur Region in the summer of 2014, fires with smoke plumes are clearly visible.
Using satellite images, it is possible to carry out environmental control of the atmospheric air, monitoring the pollution of the snow cover and smoke emissions of industrial enterprises. The figure shows a map of the ecological state of the air basin over Moscow. As you can see, the most polluted areas are the areas of railway stations and the area around the Likhachev plant.
Earth remote sensing data, thanks to the periodicity of satellite imagery, make it possible to quickly assess the situation in areas of natural disasters (floods, cyclones, droughts, earthquakes, fires) and serve as the basis for a timely forecast of natural disasters.
We see an example on the slide: two images of the same section of the coast of Indonesia in December 2004 are presented with an interval of several hours. The consequences of the tsunami that swept the coast of the Indian Ocean are clearly visible.
In the following photographs, taken at intervals of 10-15 years, one can observe the emergence of a problem associated with the drying up of Lake Chad. The Aral Sea is experiencing a similar phenomenon.
Space monitoring data can be used to take measures to prevent emergencies. Thus, regular space monitoring of the ice situation on the rivers of Siberia in the spring allows timely identification of the places of occurrence of ice jams in order to eliminate them (for example, using the explosive method) and thereby prevent the occurrence of severe flooding, leading to great social and material damage.
One of the most important tasks that can be solved using Earth remote sensing data is monitoring the development of the territory's infrastructure for the purposes of regional planning. As a rule, topographic maps are used to solve regional planning problems. But, as experience shows, these maps cease to reflect the true state of affairs within a few years after drawing up. New roads, settlements, etc. appear that are not marked on the map. All this greatly complicates the process of regional planning. In this regard, the use of Earth remote sensing systems opens up great opportunities for organizing effective regional planning, especially in the context of the rapid development of the country or its individual territories.
The figure illustrates the above. As can be seen, a comparison of the topographic map of the Tuapse region, compiled in 1994, with a satellite image of the same region in 2009 clearly shows the advantages of using Earth remote sensing systems. The image can be used to clarify the coastline, identify newly appeared objects that are not marked on the topographic map.
We made sure thatcurrently, space images are needed not only for geographers, but also for meteorologists, geologists, and cartographers. With the help of satellite images, they study the structure of the earth's crust, search for minerals, detect forest fires, and explore areas rich in fish in the ocean. Thus, the space method of studying the Earth is popular, relevant, and presents unlimited possibilities.
Not all industries and enterprises of the country have the opportunity to actively use the Earth remote sensing data. Some constituent entities of the Federation have introduced into practice the use of satellite imagery for solving regional problems. On the territory of the Yaroslavl Region, the major organizations that have introduced the use of satellite imagery are Geomonitoring for the study of groundwater, the Kadastr and Nedra companies. We found that there is a draft program for using Earth remote sensing data for planning the territory of Yaroslavl, developing its master plan. With the help of an image taken from space, it is possible to quickly identify the most congested roads in order to more efficiently plan the construction of new transport routes. Remote sensing data will be useful in planning urban development and suburban areas, in solving environmental issues, for planning a greening system and sanitary zones of enterprises. Let's hope that modern achievements in the field of space monitoring will be the basis for effective management of our region.
Already now, each of us has personal access to the results of space sensing of the Earth for use in educational purposes. A few years ago it would have been fantastic. But the launch of the first artificial Earth satellite and the first manned flight into space, even a few years before their implementation, also seemed an extraordinary fantasy.
Knowledge has a wonderful feature - it constantly reminds us that it is only a springboard to the future and we still do not know too much. The manned space walk made it possible to solve many new problems and make new discoveries. But the process of cognition is such that, solving some problems, we are faced with new unsolved problems, because the process of cognition itself is endless.
Among geophysical research methods, very reliable information gives seismic ("Seismos" in Greek means oscillation, earthquake), or seismic survey... It consists in the following: an explosion is made on the surface of the Earth. Special instruments note the speed at which the vibrations caused by the explosion propagate. With this data, geophysicists determine which rocks have been traversed by seismic waves. After all, the speed of passage of waves in different rocks is not the same. In sedimentary rocks, the speed of propagation of seismic waves is about 3 km per second, in granite, about 5 km per second.
But the data of geophysicists require verification, and in order to carry out such a verification, it is necessary to penetrate into the bowels of the Earth, to look, to investigate the rocks of which our planet consists at a depth.
Superdeep wells have been drilled in a number of countries, and over time this will help to look into the unknown. The storming of the depths of the earth has already begun, and, perhaps, soon much will become known about the bowels of the planet on which we live. These new data will help to make fuller use of the Earth's riches, both mineral and energy.
On the territory of the CIS, 11 superdeep wells were laid, among which the most famous are in the following regions: in the Caspian lowland, in the Urals, the Kola Peninsula, on the Kuril Islands, as well as in the Transcaucasia.
To penetrate deep into the Earth is not just the dream of an inquisitive person. This is a necessity, on the solution of which many important questions depend. Penetration into the bowels of the Earth will help solve a number of questions, namely: are the continents moving? Why do earthquakes and volcanic eruptions happen? What is the temperature in the bowels of the Earth? Is the globe shrinking or expanding? Why are some parts of the earth's crust slowly sinking while others are rising? As you can see, scientists have to uncover many more secrets, the key to solving which lies in the depths of our planet. Material from the site
Search for minerals
It is known that every year humanity consumes millions of tons of various minerals for its needs: oil, iron ore, mineral fertilizers, coal. All this and other mineral raw materials are given to us by the earth's interior. Only enough oil is produced in a year that it can cover the entire earth's land with a thin layer. And if a hundred or two hundred years ago, many of the named minerals were mined directly from the surface or from shallow mines, then in our time there are almost no such deposits. We have to dig deep mines, drill wells. Every year, people are digging deeper and deeper into the Earth to provide the rapidly developing industry and agriculture with the necessary raw materials.
Many scientists, especially foreign ones, have long begun to fear: "Will there be enough minerals for mankind?" Studies have shown that it is there, at a considerable depth, that metal ores and diamonds are formed. The richest deposits of coal, oil and gas are hidden in deeper earth layers.
REPEAT NECESSARY KNOWLEDGE
What conclusions can be drawn by comparing objects? (Life experience)
Comparing objects, one can draw a conclusion about their similarities and differences.
In what cases is comparison used? (Life experience)
Comparison is used when it is necessary to describe an object, to choose between several objects.
Compare the number of offspring that a pair of frogs and a pair of monkeys can give in a lifetime. Does this mean that the number of frogs is constantly growing?
The number of offspring that a pair of frogs can produce is much greater than that of a pair of monkeys. This does not mean that the number of frogs is constantly growing. Frogs have a significantly shorter lifespan, much higher mortality of young individuals (frogs).
What was the expected yield of these crops?
The crops of corn in our country in the 60s were located much north of its distribution at home. Therefore, high yields were not expected. The plant's yield in cooler climates, with shorter growing seasons, will certainly be lower.
Try to explain why submarines look like dolphins, squid and stingrays, but not jellyfish.
The streamlined body shape of a dolphin, squid, stingray, which helps to reduce drag and develop high speed under water, is more suitable for the role of a model in the creation of submarines.
Are any similarities important?
Not all similarities matter.
With whom does the bird "compare" this butterfly? What mistake is she making?
The bird compares this butterfly to an owl. The mistake is that the bird pays attention to the color of the butterfly, and the structure of its body is an essential feature.
What are the similarities between a whale and a submarine? Is it possible to draw a conclusion about the internal structure of a whale on the basis of this similarity?
The similarities between a submarine and a whale in their shape. On the basis of this fact, it is impossible to draw a conclusion about the internal structure.
What are the similarities between a scorpion fish and a perch? Is it possible to draw a conclusion about the internal structure of the scorpion on the basis of this similarity?
The similarity between the scorpion fish and the perch is only in the general plan of the structure. Their color, shape and size of fins are different. However, these signs do not make it possible to draw a conclusion about the internal structure of organisms. Since both organisms are representatives of fish, their internal structure will be similar.
APPLYING KNOWLEDGE
1. What are the most important tasks of science?
The tasks of science are forecasting based on the generalization of previous experience, the creation and improvement of the scientific worldview.
2. How do scientists manage to predict unknown properties?
Prediction allows scientists to predict unknown properties.
3. What is the comparative method?
The essence of the comparative method is to compare two or more objects according to different parameters. Comparison allows you to find common, stable, essential properties of objects, to refer them to the class of objects with known properties.
4. Can science explain a miracle?
Not all phenomena, but science can explain most of them. If scientific knowledge at this stage in the development of mankind cannot explain some facts, then, as history shows, over time everything will find its own explanation.
5. Try to define the purpose and objectives of the science of biology.
The goal is to study living organisms. The tasks of biology are to study all biological laws and disclose the essence of life.
6. How does the comparative method help to study the history of the Earth?
Comparison of strata of different ages makes it possible to reconstruct the history of the earth's development.
7. What are the essential features of cars.
Rigid body, four wheels, engine driven, fuel.
8. Work in pairs: have one find the corresponding signs of a car and a steam locomotive, and the other challenges them.
9. How has science personally helped you in life?
Science helps us every day in everyday life. It is she who gives us an understanding of why the day is replaced by night, precipitation falls, the seasons change. Scientific knowledge helps us to determine the time, to understand the importance of eating, etc.
10. Do you think it is possible to demand responsibility from a scientist for all further ways of using his scientific discoveries?
You cannot demand responsibility from a scientist for further ways of using his scientific discoveries. The history of Nobel and the invention of dynamite proves that sometimes a scientist, making a discovery, does not even think about the possible ways of its use.