Coursework: The influence of cosmic processes and phenomena on the development of the Earth. Space processes and mineral formation Space processes

Ministry of Education and Science of the Russian Federation

State educational institution of higher professional education

Altai State University

Faculty of Geography

Department of Physical Geography and GIS

Course work

The influence of cosmic processes and phenomena on the development of the Earth

Is done by a student

course 901 group

A.V. Starodubov

Candidate of Sciences, Art. teacher V.A. Bykov

Barnaul 2011

Introduction

Chapter 1. Information about the Earth

1 Magnetosphere

2 Earth's radiation belts

3 Gravity

Chapter 2. The influence of cosmic processes and phenomena on the development of the Earth

1 Impact of small cosmic bodies

1.1 Short-term consequences of a collision

2 Impact of the Sun on the Earth

Conclusion

Literature

Appendix 1

Annex 2

Annex 3

Appendix 4

Appendix 5

Appendix 6

Annex 7

abstract

This work, on the topic of the influence of cosmic processes and phenomena on the development of the Earth, is made on 48 pages.

Coursework contains 9 figures. It also contains 1 table. In addition, the abstract contains 7 applications. In addition, it is worth adding that there are 22 sources in the list of references.

Introduction

The purpose of this work is to consider the influence of the main cosmic factors and phenomena on the planet Earth.

This problem has not lost its significance. From the very first days of existence to this day, the planet depends on the influence of space. In the second half of the 20th century - the first half of the 21st century, the dependence of the planet on outer space and its impact has increased. Now, when humanity has entered the era of technological development, the risk of catastrophic consequences is especially great. Powerful solar flares, however paradoxical it may sound, entail problems for: a) commodity producers; b) ordinary citizens; c) states. Numerous devices created by man, one way or another, depend on solar activity. And their shutdown, caused by solar activity, is, first of all, a waste of time and money for the commodity producer.

The most famous researchers of the above problem are: a group of American scientists led by J. Van Allen, Soviet scientists led by S.N. Vernov and A.E. Chudakov, A. Sklyarov.

The goal is revealed through the following tasks:

Review the available literature on the topic;

Consider the influence of the Magnetic Sphere on planet Earth;

Analyze the interaction between the Van Alen Radiation Belt and the Earth;

To study the effect of gravity on the planet Earth;

Consider the consequences of the impact of small cosmic bodies;

Consider the interaction of the Sun and the Earth;

The object of research is cosmic processes and phenomena.

The subject of the study is the impact of cosmic processes and phenomena on the development of the earth.

The information base for writing the work was books, the Internet, maps, and the media. I used several methods for writing my term paper: comparative descriptive, cartographic, paleogeographic (historical and genetic), geophysical and mathematical.

Chapter 1. Information about the Earth

The Earth is the third planet from the Sun in the Solar System. It revolves around the Sun in a nearly circular orbit at an average distance of 149.6 million km. The revolution around the Sun is counterclockwise. The average speed of the Earth's orbit is 29.765 km/s, the period of revolution is 365.24 solar days or 3.147 * 10 7 s. Also, the Earth has a rotation in the forward direction, which is equal to 23 hours 56 minutes 4.1 s or 8.616 * 10 4 s.

The figure of the Earth is a geoid, i.e. equipotential surface of gravity. Outside the continents, the geoid coincides with the undisturbed surface of the World Ocean.

The mass of the Earth is Mg \u003d 5.977 * 10 27 g, the average radius R g \u003d 6371 km, the surface area of the Earth S \u003d 5.1 * 10 18 cm 2 , average density ρ= 5.52 g/cm 3 average acceleration of gravity on the earth's surface g= 9.81 Gal.

1 Magnetosphere

The magnetosphere is one of the most important spheres of the Earth. Almost all planets have magnetic fields, with the exception of Pluto and the Moon, and the Sun. The Earth's magnetic field is approximated by an infinitesimal dipole, whose axis is located 436 km from the Earth's center towards the Pacific Ocean and is inclined by 12° with respect to the Earth's rotation axis. The magnetic field lines exit from the North Magnetic Pole in the Southern Hemisphere and enter the South Magnetic Pole in the Northern Hemisphere. The magnetic poles are constantly wandering, exposed to the world's magnetic anomalies.

The origin of the magnetic field is associated with the interaction of the solid inner core, liquid outer and solid monolith, forming a kind of magnetic hydro-dynamo. The sources of the main geomagnetic field, as well as its variations, are 95% related to the internal field, and only 1% is accounted for by the external field, which experiences continuous rapid changes.

The magnetosphere has an asymmetric structure - it decreases in size from the side of the Sun to about 10 Earth radii and increases to 100 on the other side. This is due to the dynamic pressure - shock wave - solar wind particles (Ʋ=500km/s). If this pressure increases, acquiring the shape of a paraboloid, then the magnetosphere on the sunny side is flattened more strongly. The pressure weakens and the magnetosphere expands. Solar plasma flows around the magnetosphere, the outer boundary of which - the magnetopause - is located so that the pressure that the solar wind exerts on the magnetosphere is balanced by the internal magnetic pressure.

When the magnetosphere is compressed as a result of the pressure of the solar wind, a ring current arises in it, which already creates its own magnetic field, which merges with the main magnetic field, as if helping the latter to cope with pressure, and the magnetic field strength on the Earth's surface increases - this is confidently recorded.

The magnetic field is rarely calm - its strength increases sharply, then it decreases and returns to its normal value. Strong magnetic storms are caused by powerful chromospheric flares, when particles fly at speeds up to 1000 km/s, and then the ionosphere is also disturbed. 8 minutes after the flares, all short-wavelength communication may cease, since the X-ray emission strongly increases, layer D ˝ in the ionosphere, it ionizes faster and absorbs radio waves. After some time, the F 2 layer is destroyed, and the ionization maximum shifts upward (see Appendix 2).

In general, it can be seen that the ionosphere and magnetosphere are a single whole, and at the same time, the daily rotation of the Earth makes them also rotate, and only above 30 thousand km, the plasma no longer responds to the rotation of the Earth. With the help of spacecraft, the boundary of the magnetosphere was determined.

2 Earth's radiation belts

The inner regions of the Earth's magnetosphere, in which the Earth's magnetic field traps charged particles (protons<#"539410.files/image001.gif">with characteristic values g » 1.8 for protons in the energy range from 40 to 800 MeV, E 0 ~ 200-500 keV for outer and inner belt electrons, and E 0 ~ 100 keV for low-energy protons (1).

The origin of trapped particles with energies significantly exceeding the average energy of the thermal motion of atoms and molecules of the atmosphere is associated with the action of several physical mechanisms: the decay of neutrons created by cosmic rays in the Earth's atmosphere (the protons formed in this process replenish the internal R. p. Z.); "pumping" particles into belts during geomagnetic disturbances (magnetic storms ), which primarily determines the existence of electrons in the inner belt; acceleration and slow transfer of particles of solar origin from the outer to the inner regions of the magnetosphere (this is how the electrons of the outer belt and the belt of low-energy protons are replenished). Penetration of solar wind particles into the R. p. Z. is possible through special points of the magnetosphere, as well as through the so-called. the neutral layer in the tail of the magnetosphere (from its night side).

In the region of daytime cusps and in the neutral layer of the tail, the geomagnetic field is sharply weakened and is not a significant obstacle for charged particles of the interplanetary plasma. Polar cusps - funnel-shaped regions in the frontal part of the magnetopause at geomagnetic latitudes ~ 75°, resulting from the interaction of the solar wind and the earth's magnetic field . Through the cusp particles of the solar wind can easily penetrate into the polar ionosphere .

Partially, R. p. Z. are also replenished due to the capture of protons and electrons of solar cosmic rays penetrating into the inner regions of the magnetosphere. The enumerated sources of particles are apparently sufficient for the creation of R. p. Z. with a characteristic distribution of particle fluxes. In R. p. Z. there is a dynamic equilibrium between the processes of replenishment of belts and the processes of loss of particles. Basically, particles leave R. p. Z. due to the loss of their energy for ionization (this reason limits, for example, the stay of protons of the inner belt in a magnetic trap by the time t ~ 10 9 sec), due to the scattering of particles during mutual collisions and scattering by magnetic inhomogeneities and plasma waves of various origins. Scattering can reduce the "lifetime" of electrons in the outer belt to 10 4 -10 5 sec. These effects lead to a violation of the conditions for the steady motion of particles in a geomagnetic field (the so-called adiabatic invariants) and to the “scattering” of particles from the R. p. Z. into the atmosphere along the lines of force of the magnetic field.

Radiation belts experience various time variations: the inner belt, located closer to the Earth and more stable, is insignificant, the outer belt is the most frequent and strong. The internal solar radiation is characterized by small variations during the 11-year cycle of solar activity. The outer belt noticeably changes its boundaries and structure even with minor disturbances of the magnetosphere. The low-energy proton belt occupies an intermediate position in this sense. Especially strong variations in R. p. Z. undergo during magnetic storms. . First, in the outer belt, the flux density of low-energy particles increases sharply, and at the same time, a significant fraction of high-energy particles is lost. Then there is the capture and acceleration of new particles, as a result of which particle flows appear in the belts at distances usually closer to the Earth than in calm conditions. After the compression phase, a slow, gradual return of R. p. Z. to its original state occurs. During periods of high solar activity, magnetic storms occur very often, so that the effects of individual storms overlap each other, and the maximum of the outer belt during these periods is closer to the Earth (L ~ 3.5) than during periods of minimum solar activity (L ~ 4.5-5.0).

Precipitation of particles from a magnetic trap, especially from the zone of quasi-trapping (auroral radiation), leads to increased ionization of the ionosphere, and intense precipitation leads to auroras. The supply of particles in the R. p. Z., however, is insufficient to maintain a prolonged aurora, and the connection of auroras with variations in particle fluxes in the R. p. Z. speaks only of their general nature, i.e., that in During magnetic storms, particles are both pumped into the R. p. Z. and discharged into the Earth's atmosphere. Polar lights last all the time while these processes are going on - sometimes a day or more. R. p. Z. can also be created artificially: during the explosion of a nuclear device at high altitudes; during the injection of artificially accelerated particles, for example, using an accelerator on board the satellite; when radioactive substances are sprayed in the near-Earth space, the decay products of which will be captured by the magnetic field. The creation of artificial belts during the explosion of nuclear devices was carried out in 1958 and in 1962. Thus, after the American nuclear explosion (July 9, 1962), about 10 25 electrons with an energy of ~ 1 MeV were injected into the inner belt, which exceeded the intensity of the natural electron flux by two or three orders of magnitude. The remnants of these electrons have been observed in the belts over a period of almost 10 years.

Historically, the inner belt was discovered first (by a group of American scientists led by J. Van Allen, 1958) and the outer belt (by Soviet scientists led by S.N. Vernov and A.E. Chudakov, 1958). Fluxes of R. p. Z. particles were registered by instruments (counters - Geiger-Muller ) installed on artificial satellites of the Earth. In essence, R. p. Z. do not have clearly defined boundaries, because each type of particles, in accordance with its energy, forms its own radiation belt, therefore it is more correct to speak of one single radiation belt of the Earth. The division of R. p. Z. into external and internal, adopted at the first stage of research and preserved to this day due to a number of differences in their properties, is essentially conditional.

The fundamental possibility of the existence of a magnetic trap in the Earth's magnetic field was shown by the calculations of K. Störmer a(1913) and H. Alfven (1950), but only satellite experiments showed that the trap actually exists and is filled with high-energy particles.

1.3 Gravity

In the solar system, there are powerful forces of gravity - gravity. The sun and planets are attracted to each other. In addition, each planet has its own gravitational field. This force is greater, the greater the mass of the planet, and also the closer the body is to it.

The Earth's gravitational field can be represented as a large sphere in which the lines of force are directed towards the center of the planet. In him. In the same direction, the attractive force acting on each point of the geosphere increases. This force is enough to prevent the water of the oceans from flowing from the surface of the Earth. Water is held in depressions, but easily spreads over a flat surface.

The forces of gravity constantly act on the substance of the Earth. Heavier particles are attracted to the core, displacing lighter particles that float towards the earth's surface. There is a slow counter-movement of light and heavy matter. This phenomenon is called gravitational differentiation. As a result, geospheres with different average density of matter were formed in the body of the planet.

The mass of the Earth is more than 80 times the mass of its satellite. Therefore, the Moon is kept in near-Earth orbit and, due to the huge mass of the Earth, constantly shifts towards its geometric center by 2 - 3 km. The Earth also experiences the attraction of its satellite, despite the huge distance - 3.84 * 105 km.

"Lunar tides" are the most noticeable impact. Every 12 hours and 25 minutes, under the influence of the mass of the Moon, the level of the Earth's oceans rises, on average by 1 m. After 6 hours, the water level drops. At different latitudes, this level is different. In the Sea of Okhotsk and the Bering Sea - 10m, in the Bay of Fundy - 18m. Tidal "humps" of a solid surface are less than 35 cm. Due to the long duration of such a wave, such pulsations are imperceptible without special measurements. However, it is worth noting that waves are constantly moving along the surface of the Earth at a speed of 1000 km / h.

cosmic sun gravitational earth

Chapter 2. The influence of cosmic processes and phenomena on the development of the Earth

1 Impact of small cosmic bodies

In general, celestial bodies capable of "attacking" the Earth are called meteoroids (meteorite bodies) - these are either fragments of asteroids colliding in outer space, or fragments remaining during the evaporation of comets. If meteoroids reach the earth's atmosphere, they are called meteors (sometimes fireballs), and if they fall on the earth's surface, they are called meteorites (see Appendix 4).

Now, 160 craters have been identified on the surface of the Earth, which arose from a collision with cosmic bodies. Here are six of the most notable:

thousand years ago, the Berringer crater (Arizona, USA), circumference 1230 m - from a meteorite fall with a diameter of 50 m. This is the very first meteorite fall crater discovered on Earth. It was called "meteorite". In addition, it has been preserved better than others.

million years ago, the crater of Chesapeake Bay (Maryland, USA), circumference 85 km - from the fall of a meteorite with a diameter of 2-3 km. The catastrophe that created it shattered the rock base 2 km deep, creating a reservoir of salt water, which to this day affects the distribution of underground water flows.

5 million years ago, Popigai crater (Siberia, Russia), circumference 100 km - from the fall of an asteroid with a diameter of 5 km. The crater is strewn with industrial diamonds, which arose as a result of exposing graphite to monstrous pressures upon impact.

million years ago, Chicxulub basin (Yucatan, Mexico), circumference 175 km - from the fall of an asteroid with a diameter of 10 km. It is assumed that the explosion of this asteroid caused a grandiose tsunami and earthquakes of magnitude 10.

85 billion years ago, Sudbury crater (Ontario, Canada), circumference 248 km - from the fall of a comet with a diameter of 10 km. At the bottom of the crater, thanks to the heat released during the explosion and the water reserves contained in the comet, a system of hot springs arose. Along the perimeter of the crater, the world's largest deposits of nickel and copper ore were found.

billion years ago, the Vredefort dome (South Africa), a circle of 378 km - from the fall of a meteorite with a diameter of 10 km. The oldest and (at the time of the disaster) the largest of these craters on Earth. It arose as a result of the most massive release of energy in the entire history of our planet.

Admittedly, the most impressive discoveries of recent years in the field of paleoclimatology have been made during the drilling of ice sheets and ice core studies in the central regions of Greenland and Antarctica, where the ice surface almost never melts, which means that the information contained in it about the temperature of the surface layer of the atmosphere is stored on century. The joint efforts of Russian, French and American scientists on the isotopic composition of the ice core from an ultra-deep ice well (3350m) at the Russian Antarctic station Vostok managed to recreate the climate of our planet for this period. So, the average temperature in the area of the station "Vostok" for these 420 thousand years fluctuated from about - 54 to - 77 ° C. Thirdly, during the last "ice age" (20 - 10 thousand years ago), the climate in the middle lane Russia, including Siberia, differed little from today, especially in summer. This is evidenced by the isotopic marker of atmospheric precipitation, which has been preserved for hundreds of thousands of years in the ice of polar glaciers and in permafrost, soil carbonates, phosphates of mammalian bones, tree rings, etc. The main danger on a global scale is represented by asteroids with a radius greater than 1 km. Collision with smaller bodies can cause significant local destruction (Tunguska phenomenon), but does not lead to global consequences. The larger the asteroid, the less likely it is to hit the Earth.

Every year, 2-3 passages are recorded at a distance of 0.5-3 million km from the Earth of bodies with a diameter of 100-1000m. By neglecting, in a rough calculation, the gravitational attraction from the Earth and assuming collisions to be random, one can determine the frequency of collisions with bodies of a given size. To do this: it is necessary to multiply the cross section of the Earth, equal to 4 Pi (6400 km) 2 (2), by the frequency of the passage of an asteroid per 1 km 2 - it is approximately ~ 3/4 Pi 1.7 million km 2 (3). The reciprocal of the calculated value and will be equal to the number of years that pass on average between two collisions. The figure turns out to be ~ 25 thousand years (in fact, it is somewhat less, if we also take into account the influence of the earth's gravity and the fact that some spans went unnoticed). This is in good agreement with the data.

Collisions with large asteroids are quite rare, compared with the length of human history. However, the rarity of the phenomenon does not mean periodicity; therefore, given the random nature of the phenomenon, collisions at any moment of time cannot be ruled out - unless the probability of such a collision is quite small in relation to the probability of other catastrophes threatening an individual person (natural disasters, accidents, etc.). However: on a geological and even biological time scale, collisions are not uncommon. Over the entire history of the Earth, several thousand asteroids with a diameter of about 1 km and dozens of bodies with a diameter of more than 10 km have fallen on it. Life on Earth has existed for much longer. Although many assumptions are made about the catastrophic effects of collisions on the biosphere, none of them has yet received conclusive evidence. Suffice it to mention that not all experts agree with the hypothesis of the extinction of dinosaurs due to the collision of the Earth with a large asteroid 65 thousand years ago. Opponents of this idea (they include many paleontologists) have many reasonable objections. They indicate that the extinction occurred gradually (millions of years) and affected only some species, while others did not noticeably suffer during the division of epochs. A global catastrophe would inevitably affect all species. In addition, in the biological history of our planet, the disappearance from the scene of a number of species has repeatedly happened, but experts are not able to confidently connect these phenomena with any catastrophe.

The diameters of asteroids vary from a few meters to hundreds of kilometers. Unfortunately, only a small part of asteroids has been discovered so far. Bodies of the order of 10 km or less are difficult to detect and may go unnoticed until the very moment of the collision. The list of still undiscovered bodies of larger diameter can hardly be considered significant, since the number of large asteroids is significantly less than the number of small ones. Apparently, there are practically no potentially dangerous asteroids (that is, in principle, capable of colliding with the Earth over a period of about millions of years), whose diameter would exceed 100 km. The speeds at which collisions with asteroids occur can range from ~5 km/s to ~50 km/s, depending on the parameters of their orbits. Researchers agree that the average collision velocity should be ~(15-25) km/s.

Collisions with comets are even less predictable, since most comets arrive in the inner regions of the solar system, as it were, from "nowhere", that is, from regions very far from the Sun. They go unnoticed until they get close enough to the Sun. From the moment of discovery to the passage of the comet through perihelion (and to a possible collision) no more than a few years pass; then the comet moves away and disappears again into the depths of space. Thus, there is very little time left to take the necessary measures and prevent a collision (although the approach of a large comet cannot go unnoticed, unlike an asteroid). Comets approach the Earth much faster than asteroids (this is due to the strong elongation of their orbits, and the Earth is near the point of closest approach of the comet to the Sun, where its speed is maximum). The collision speed can reach ~70 km/s. At the same time, the sizes of large comets are not inferior to the sizes of medium-sized asteroids ~(5-50) km (their density, however, is less than the density of asteroids). But precisely because of the high speed and comparative rarity of the passage of comets through the inner regions of the solar system, their collisions with our planet are unlikely.

Collision with a large asteroid is one of the largest phenomena on the planet. Obviously, it would have an impact on all the shells of the Earth without exception - the lithosphere, atmosphere, ocean and, of course, the biosphere. There are theories describing the formation of impact craters; the impact of the collision on the atmosphere and climate (most important in terms of impact on the planet's biosphere) is similar to nuclear war scenarios and major volcanic eruptions, which also lead to the release of large amounts of dust (aerosol) into the atmosphere. Of course, the scale of phenomena to a decisive extent depends on the energy of the collision (that is, primarily on the size and speed of the asteroid). It was found, however, that when considering powerful explosive processes (starting from nuclear explosions with a TNT equivalent of several kilotons and up to the fall of the largest asteroids), the principle of similarity is applicable. According to this principle, the pattern of occurring phenomena retains its common features on all scales of energy.

Pi D3 ro/6 (4),

The density of the asteroid, v and D are its mass, speed and diameter.

Densities of cosmic bodies can vary from 1500 kg/m3 for cometary nuclei to 7000 kg/m3 for iron meteorites. Asteroids have an iron-stony composition (different for different groups). It can be taken as the density of the falling body. ro~5000 kg/m3. Then the collision energy will be E ~ 5 1023 J. In TNT equivalent (an explosion of 1 kg of TNT releases 4.2 106 J of energy) this will be ~ 1.2 108 Mt. The most powerful of the thermonuclear bombs tested by mankind, ~100 Mt, had a million times less power.

Energy scales of natural phenomena

One should also keep in mind the time during which the energy is released and the area of the event zone. Earthquakes occur over a large area, and energy is released in the order of hours; damage is moderate and evenly distributed. During bomb explosions and meteorite falls, local destruction is catastrophic, but their scale rapidly decreases with distance from the epicenter. Another conclusion follows from the table: despite the colossal amount of energy released, in terms of scale, the fall of even large asteroids is comparable to another powerful natural phenomenon - volcanism. The explosion of the Tambora volcano was not the most powerful even in historical time. And since the energy of the asteroid is proportional to its mass (that is, the cube of the diameter), then when a body with a diameter of 2.5 km fell, less energy would be released than when Tambor exploded. The explosion of the Krakatoa volcano was equivalent to the fall of an asteroid with a diameter of 1.5 km. The influence of volcanoes on the climate of the entire planet is generally recognized, however, it is not known that large volcanic explosions were catastrophic (we will return to the comparison of the impact on the climate of volcanic eruptions and asteroid falls).

Bodies with a mass of less than 1 ton are almost completely destroyed when flying through the atmosphere, while a fireball is observed. Often, a meteorite completely loses its initial velocity in the atmosphere and, upon impact, already has a free fall velocity (~200 m/s), forming a depression slightly larger than its diameter. However, for large meteorites, the loss of velocity in the atmosphere practically does not play a role, and the phenomena accompanying the supersonic passage are lost in comparison with the scale of phenomena occurring during the collision of an asteroid with the surface.

Formation of explosive meteorite craters in a layered target (see Appendix 5):

a) The beginning of penetration of the impactor into the target, accompanied by the formation of a spherical shock wave propagating downwards;

b) the development of a hemispherical crater funnel, the shock wave has broken away from the contact zone of the striker and the target and is accompanied from the rear by an overtaking unloading wave, the unloaded substance has a residual velocity and spreads to the sides and upwards;

c) further formation of the transition crater funnel, the shock wave attenuates, the bottom of the crater is lined with shock melt, a continuous curtain of ejecta spreads outward from the crater;

d) the end of the excavation stage, the growth of the funnel stops. The modification stage proceeds differently for small and large craters.

In small craters, slipping into a deep funnel of non-cohesive material of the walls - impact melt and crushed rocks. When mixed, they form an impact breccia.

For large-diameter transition funnels, gravity begins to play a role - due to gravitational instability, the crater bottom bulges upwards with the formation of a central uplift.

The impact of a massive asteroid on rocks creates pressures that cause the rock to behave like a liquid. As the asteroid deepens into the target, it carries with it ever greater masses of matter. At the impact site, the asteroid's substance and the surrounding rocks instantly melt and evaporate. Powerful shock waves arise in the soil and body of the asteroid, which move apart and throw the substance to the sides. The shock wave in the ground moves ahead of the falling body somewhat ahead of it; shock waves in the asteroid first compress it, and then, reflected from the rear surface, tear it apart. The pressure developed in this case (up to 109 bar) is sufficient for the complete evaporation of the asteroid. There is a powerful explosion. Studies show that for large bodies the center of the explosion is located near the surface of the earth or slightly lower, that is, a ten-kilometer asteroid deepens 5-6 km into the target. During the explosion, the substance of the meteorite and the surrounding crushed rocks are ejected from the resulting crater. The shock wave propagates in the ground, losing energy and destroying rocks. When the destruction limit is reached, the growth of the crater stops. Having reached the interface between media with different strength properties, the shock wave is reflected and lifts the rocks in the center of the formed crater - this is how the central uplifts observed in many lunar cirques arise. The bottom of the crater consists of destroyed and partially melted rocks (breccias). To them are added fragments thrown out of the crater and falling back, filling the circus.

Approximately, you can specify the dimensions of the resulting structure. Since the crater is formed as a result of an explosive process, it has an approximately circular shape, regardless of the angle of impact of the asteroid. Only at small angles (up to >30° from the horizon) is some elongation of the crater possible. The volume of the structure significantly exceeds the size of the fallen asteroid. For large craters, the following approximate relationship has been established between its diameter and the energy of the asteroid that formed the crater: E~D4, where E is the energy of the asteroid and D is the diameter of the crater. The diameter of the crater formed by a 10 km asteroid will be 70-100 km. The initial depth of the crater is usually 1/4-1/10 of its diameter, that is, in our case, 15-20 km. Filling with debris will slightly reduce this value. The boundary of rock fragmentation can reach a depth of 70 km.

The removal of such a quantity of rock from the surface (leading to a decrease in pressure on the deep layers) and the entry of a fragmentation zone into the upper mantle can cause volcanic phenomena to occur at the bottom of the formed crater. The volume of evaporated matter will probably exceed 1000 km 3 ; the volume of molten rock will be 10, and crushed - 10,000 times higher than this figure (energy calculations confirm these estimates). Thus, several thousand cubic kilometers of molten and destroyed rock will be thrown into the atmosphere.

The fall of an asteroid on the water surface (more likely, based on the ratio of the area of \u200b\u200bthe continents and land on our planet) will have similar features. The lower density of water (meaning less energy loss when penetrating into the water) will allow the asteroid to go deeper into the water column, up to hitting the bottom, and explosive destruction will occur at a greater depth. The shock wave will reach the bottom and form a crater on it, and in addition to the rock from the bottom, about several thousand cubic kilometers of water vapor and aerosol will be ejected into the atmosphere.

There is a significant analogy between what happens in the atmosphere in a nuclear explosion and in an asteroid impact, of course, given the difference in scale. At the moment of collision and explosion of the asteroid, a giant fireball is formed, in the center of which the pressure is extremely high, and the temperatures reach millions of kelvins. Immediately after formation, a ball consisting of evaporated rocks (water) and air begins to expand and float in the atmosphere. The shock wave in the air, propagating and fading, will retain its destructive ability up to several hundred kilometers from the epicenter of the explosion. Rising, the fireball will carry along a huge amount of rock from the surface (since when it rises, a vacuum is formed under it). As it rises, the fireball expands and deforms into a toroid, forming a characteristic "mushroom". As more and more air masses expand and are involved in the movement, the temperature and pressure inside the ball fall. The ascent will continue until the pressure is balanced by the external one. In kiloton explosions, the fireball is balanced to heights below the tropopause (<10 км). Для более мощных, мегатонных взрывов шар проникает в стратосферу. Огненный шар, образовавшийся при падении астероида, поднимется ещё выше, возможно, до 50-100 км (поскольку подъём происходит за счёт зависящей от плотности среды архимедовой силы, а с высотой плотность атмосферы быстро падает, больший подъём невозможен). Постепенно остатки огненного шара рассеиваются в атмосфере. Значительная часть испарённой породы конденсируется и выпадает локально, вместе с крупными кусками и затвердевшим расплавом. Наиболее мелкие аэрозольные частицы остаются в атмосфере и разносятся.

1.1 Short-term consequences of a collision

It is quite obvious that local destruction will be catastrophic. At the place of impact, an area with a diameter of more than 100 km will be occupied by a crater (together with a rampart). A seismic shock caused by a shock wave in the ground will be destructive in a radius of more than 500 km, as well as a shock wave in the air. On a smaller scale, areas that may be up to 1500 km from the epicenter will undergo destruction.

It would be appropriate to compare the consequences of the fall with other earthly catastrophes. Earthquakes, having a significantly lower energy, however, cause destruction over large areas. Complete destruction is possible at distances of several hundred kilometers from the epicenter. It should also be taken into account that a significant part of the population is concentrated in seismically hazardous zones. If we imagine the fall of an asteroid of a smaller radius, then the area of destruction caused by it will decrease approximately in proportion to 1/2 of the degree of its linear dimensions. That is, for a body with a diameter of 1 km, the crater will be 10-20 km in diameter, and the radius of the destruction zone will be 200-300 km. This is even less than during large earthquakes. In any case, with colossal local destruction, there is no need to talk about the global consequences of the explosion itself on land.

The consequences of falling into the ocean can lead to a catastrophe on a large scale. The fall will be followed by a tsunami. It is difficult to judge the height of this wave. According to some assumptions, it can reach hundreds of meters, but I do not know the exact calculations. It is obvious that the mechanism of wave generation here differs significantly from the mechanism of generation of most tsunamis (during underwater earthquakes). A real tsunami, capable of spreading over thousands of kilometers and reaching the shores, must have a sufficient length in the open ocean (one hundred or more kilometers), which is ensured by an earthquake that occurs during a long fault shift. It is not known whether a powerful underwater explosion will provide a long wave. It is known that during tsunamis resulting from underwater eruptions and landslides, the wave height is indeed very large, but due to its short length, it cannot spread across the entire ocean and decays relatively quickly, causing destruction only in adjacent areas (see below) . In the case of a huge real tsunami, a picture would be observed - colossal destruction in the entire coastal zone of the ocean, flooding of the islands, up to heights below the height of the wave. When an asteroid falls into a closed or limited body of water (inland or inter-island sea), practically only its coast will be destroyed.

In addition to the destruction directly associated with the fall and immediately following it, one should also consider the long-term consequences of the collision, its impact on the climate of the entire planet and the possible damage caused to the Earth's ecosystem as a whole. Press reports are full of warnings about the onset of "nuclear winter" or vice versa, "greenhouse effect" and global warming. Let's consider the situation in more detail.

As mentioned above, the fall of a 10-kilometer asteroid will lead to a simultaneous release into the atmosphere of up to 104 thousand km 3 of matter. However, this figure is probably overestimated. According to calculations for nuclear explosions, the volume of ejected soil is about 100 thousand tons/Mt for less powerful explosions and slowly decreases starting from a yield of 1 Mt. Proceeding from this, the mass of the ejected substance will not exceed 1500 km 3 . Note that this figure is only ten times higher than the release of the Tambora volcano in 1815 (150 thousand km 3). The bulk of the ejected material will be large particles that will fall out of the atmosphere over several hours or days directly in the area of impact. Long-term climatic consequences should be expected only from submicron particles thrown into the stratosphere, where they can remain for a long time and will be spread over the entire surface of the planet in about half a year. The share of such particles in the emission can be up to 5%, that is, 300 billion tons. Per unit area of the earth's surface, this will be 0.6 kg / m 2 - a layer of about 0.2 mm thick. At the same time, 10 tons of air and >10 kg of water vapor fall on 1 m2.

Due to the high temperatures at the site of the explosion, the ejected substance contains practically no smoke and soot (that is, organic matter); but some soot will be added as a result of fires that can cover areas in the epicenter area. Volcanism, the manifestations of which are not excluded at the bottom of the resulting crater, will not exceed ordinary eruptions in scale, and therefore will not add a significant contribution to the total mass of the ejecta. When an asteroid falls into the ocean, thousands of cubic kilometers of water vapor will be thrown out, but compared to the total amount of water contained in the atmosphere, its contribution will be insignificant.

In general, the effect of a substance released into the atmosphere can be considered within the framework of scenarios for the consequences of a nuclear war. Although the asteroid explosion would be ten times more powerful than the combined power of the explosions in the most severe scenario mentioned, its local nature, in contrast to the planet-wide war, causes the expected consequences to be similar (for example, the explosion of a 20-kiloton bomb over Hiroshima led to destruction equivalent to a conventional bombardment of a total explosive power of 1 kiloton of TNT bombs).

There are many assumptions about the impact of a large amount of aerosol released into the atmosphere on the climate. A direct study of these effects is possible in the study of large volcanic eruptions. Observations show, in general, that during the most powerful eruptions, immediately after which several cubic kilometers of aerosol remain in the atmosphere, in the next two to three years, summer temperatures drop everywhere and winter temperatures rise (within 2-3 °, on average, much less) . There is a decrease in direct solar radiation, the proportion of scattered increases. The proportion of radiation absorbed by the atmosphere increases, the temperature of the atmosphere rises, and the surface temperature falls. However, these effects do not have a long-term character - the atmosphere clears up rather quickly. Over a period of about six months, the amount of aerosol decreases tenfold. So, a year after the explosion of the Krakatoa volcano, about 25 million tons of aerosol remained in the atmosphere, compared with the initial 10-20 billion tons. It is reasonable to assume that after the fall of the asteroid, the purification of the atmosphere will occur at the same pace. It should also be taken into account that a decrease in the flow of energy received will be accompanied by a decrease in the flow of energy lost from the surface, due to increased screening - the "greenhouse effect". Thus, if the fall is followed by a drop in temperatures by several degrees, in two or three years the climate will practically return to normal (for example, in a year about 10 billion tons of aerosol will remain in the atmosphere, which is comparable to what was immediately after the explosion of Tambora or Krakatau).

The fall of an asteroid, of course, represents one of the biggest disasters for the planet. Its impact is easily comparable to other, more frequent natural disasters, such as an explosive volcanic eruption or a major earthquake, and may even surpass them in terms of impact. The fall leads to total local destruction, and the total area of the affected area can reach several percent of the entire area of the planet. However, the fall of really large asteroids that can have a global impact on the planet are quite rare on the scale of the lifetime of life on Earth.

A collision with small asteroids (up to 1 km in diameter) will not lead to any noticeable planetary consequences (excluding, of course, an almost unbelievable direct hit in the region of accumulation of nuclear materials).

A collision with larger asteroids (approximately from 1 to 10 km in diameter, depending on the speed of the collision) is accompanied by a powerful explosion, the complete destruction of the fallen body and the release of up to several thousand cubic meters of rock into the atmosphere. In terms of its consequences, this phenomenon is comparable to the largest catastrophes of terrestrial origin, such as explosive volcanic eruptions. The destruction in the impact zone will be total, and the climate of the planet will change abruptly and return to normal only in a few years. The exaggeration of the threat of a global catastrophe is confirmed by the fact that in its history the Earth has suffered many collisions with similar asteroids and this has not left a noticeable trace in its biosphere (in any case, it has not always left).

Among the works known to us on meteorite themes, perhaps the most elegant and scrupulously worked out is Andrey Sklyarov's The Myth of the Flood. Sklyarov studied many myths of different peoples, compared them with archaeological data and came to the conclusion that in the 11th millennium BC. a large meteorite fell to Earth. According to his calculations, a meteorite with a radius of 20 km flew at a speed of 50 km / s, and this happened in the period from 10480 to 10420 BC.

A meteorite that fell almost tangentially to the earth's surface in the Philippine Sea region caused the earth's crust to slip through magma. As a result, the crust turned relative to the axis of rotation of the globe, and a shift of the poles occurred. In addition to the displacement of the earth's crust relative to the poles, which then led to a redistribution of glacial masses, the fall was accompanied by tsunamis, the activation of volcanoes, and even the tilt of the Philippine oceanic plate, which resulted in the formation of the Mariana Trench.

First, over the past 60 million years, the equatorial level of the world's oceans has not changed significantly. Evidence of this is obtained (in the form of a side effect) when drilling wells on the atolls in search of a test site for testing hydrogen bombs. In particular, wells on Eniwetok Atoll, located on the slope of an oceanic trench and gradually sinking, have shown that over the past 60 million years, a coral layer has been continuously growing on it. This means that the temperature of the surrounding ocean waters during all this time did not fall below +20 degrees. In addition, there were no rapid changes in ocean level in the equatorial zone. The Eniwetok atoll is close enough to the meteorite fall site proposed by Sklyarov, and the corals would inevitably suffer, which was not found.

Secondly, over the past 420 thousand years, the average annual temperature of the Antarctic ice sheet has not risen above minus 54 0 C, and the shield has never disappeared during this entire period.

Through the joint efforts of Russian, French and American scientists on the isotopic composition of the ice core from an ultra-deep ice hole (3350 m) at the Russian Antarctic station Vostok, it was possible to recreate the climate of our planet for this period. So, the average temperature in the area of the station "Vostok" for these 420 thousand years fluctuated from about - 54 to - 77 ° C.

Thirdly, during the last "Ice Age" (20 - 10 thousand years ago), the climate in central Russia, including Siberia, differed little from today, especially in summer. This is evidenced by the isotopic marker of atmospheric precipitation, which has been preserved for hundreds of thousands of years in the ice of polar glaciers and in permafrost, soil carbonates, phosphates of mammalian bones, tree rings, etc.

2 Impact of the Sun on the Earth

An equally important factor in the development of the Earth is solar activity. Solar activity is a set of phenomena on the Sun associated with the formation of sunspots, torches, floccules, fibers, prominences, the occurrence of flares, accompanied by an increase in ultraviolet, X-ray and corpuscular radiation.

The strongest manifestation of solar activity affecting the Earth, solar flares. They appear in active regions with a complex structure of the magnetic field and affect the entire thickness of the solar atmosphere. The energy of a large solar flare reaches a huge value, comparable to the amount of solar energy received by our planet for a whole year. This is approximately 100 times more than all the thermal energy that could be obtained by burning all the explored mineral reserves.

This is the energy emitted by the entire Sun in 1/20 of a second, with a power not exceeding hundredths of a percent of the power of the total radiation of our star. In flare-active regions, the main sequence of flares of high and medium power occurs over a limited time interval (40-60 hours), while small flares and glows are observed almost constantly. This leads to an increase in the general background of the electromagnetic radiation of the Sun. Therefore, to assess solar activity associated with flares, they began to use special indices directly related to real fluxes of electromagnetic radiation. According to the magnitude of the radio emission flux at a wave of 10.7 cm (frequency 2800 MHz), in 1963 the index F10.7 was introduced. It is measured in solar flux units (sfu). It is worth considering that 1 s.u. \u003d 10-22 W / (m 2 Hz). The F10.7 index is in good agreement with the changes in the total sunspot area and the number of flares in all active regions.

The catastrophe that broke out in the Asia-Pacific region in March 2010 can clearly tell about the consequences of a solar flare. Outbreaks were observed from March 7 to 9, the minimum score is C1.4, the maximum is M5.3. The first to react to the disturbance of the magnetic field on March 10, 2011 at 04:58:15 (UTC time) was an earthquake, the hypocenter at a depth of 23 km. The magnitude was 5.5. The next day - another outbreak, but even more powerful. The outbreak of the X1.5 score is one of the strongest in recent years. The answer of the Earth - at first an earthquake of magnitude 9.0; the hypocenter was located at a depth of -32 km. The epicenter of the earthquake was located 373 km from the capital of Japan, Tokyo. The earthquake was followed by a devastating tsunami that changed the face of the east coast of about. Honshu. Volcanoes also responded to a powerful outbreak. Volcano Karangetang, considered one of the most active in Indonesia, began to erupt on Friday, a few hours after a powerful earthquake in Japan. The Japanese volcanoes Kirishima and Sinmoe began to erupt.

From March 7 to March 29, solar activity is higher than usual, and from March 7 to 29, earthquakes do not stop in the Asia-Pacific, Indian regions (AT. region - magnitude from 4, and region - magnitude from 3).

Conclusion

As a result of viewing the available literature on the topic and on the basis of the goals and objectives set, several conclusions can be drawn.

The magnetosphere is one of the most important spheres of the Earth. Abrupt changes in the magnetic field, i.e. magnetic storms can penetrate the atmosphere. The most striking example of the impact is the shutdown of electrical appliances, which include microcircuits and transistors.

Radiation belts play an important role in interaction with the Earth. Thanks to the belts, the Earth's magnetic field holds charged particles, namely: protons, alpha particles and electrons.

Gravity is one of the most important important processes affecting the development of the Earth. The forces of gravity constantly act on the substance of the Earth. As a result of gravitational differentiation, geospheres with different average density of matter were formed in the body of the planet.

Small cosmic bodies are no less important factor in the interaction of the "Space - Earth" system. It is worth considering that a large asteroid falling into the ocean will raise a destructive wave that will circle the globe several times, sweeping away everything in its path. If an asteroid hits the mainland, then a layer of dust will rise into the atmosphere, which will block sunlight. There will be an effect of the so-called nuclear winter.

Perhaps the most important factor is solar activity. The events of March 10-11, 2011 can serve as an example of the interaction between the Sun and the Earth. During this period of time, after a powerful outbreak, on about. Honshu was hit by an earthquake, followed by a tsunami, and then volcanoes woke up.

Thus, space processes are the determining factor in the interaction of the "Space-Earth" system. Also, it is important that in the absence of the above phenomena, life on the planet could not exist.

Literature

1. Gnibidenko, Z.N., / Paleomagnetism of the Cenozoic of the West Siberian Plate / Geo. - Novosibirsk, 2006. - S. 146-161

Sorokhtin, O.V. // Theory of the Earth's development: origin, evolution and tragic future / RANS. - M., 2010. - P. 722-751

Krivolutsky, A.E. / Blue planet / Thought. - M., 1985.- P.326-332

Byalko, A.V. / Our planet is the Earth/ Science. - M., 1989.- P.237

Khain, V.E./ Planet Earth/ Moscow State University Geol. fak. - M., 2007.- S.234-243

Leonov, E.A. // Space and ultra-long hydrological forecast/ Nauka. - M., 2010

Romashov, A.N. / Planet Earth: Tectonophysics and evolution / Editorial URSS - M., 2003

Todhunter, I. / /History of mathematical theories of attraction and the figure of the Earth from Newton to Laplace/Editorial URSS. - M., 2002.- P.670

Vernov S.N. Radiation belts of the Earth and cosmic rays / S.N. Vernov, P.V. Vakulov, E.V. Gorchakov, Yu.I. Logachev.-M.: Enlightenment, 1970.- P.131

Hess V. // Radiation belt and the Earth's magnetosphere / Atomizdat. - M., 1973. - P. 423

Roederer X. // Dynamics of radiation captured by the geomagnetic field / Mir. - M, 1972. - S. 392

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Space phenomena and processes- events of cosmic origin, connecting or capable of having a damaging effect on people, agricultural animals and plants, economic facilities and the natural environment. Such cosmic phenomena can be the fall of cosmic bodies and dangerous cosmic radiation.

Humanity has an enemy more dangerous than a nuclear bomb, global warming or AIDS. Currently, about 300 space bodies are known that can cross the earth's orbit. Basically, these are asteroids ranging in size from 1 to 1000 km. In total, about 300,000 asteroids and comets have been discovered in space. Until the last moment, we may not know anything about the approaching catastrophe. Scientists astronomers admitted that the most modern space tracking systems are very weak. At any moment, a killer asteroid, rapidly approaching the Earth, can “emerge” directly from the abyss of space, and our telescopes will detect it only when it is too late.

Over the entire history of the earth, collisions with cosmic bodies with a diameter of 2 to 100 km are known, of which there were more than 10.

Reference: On the morning of June 30, 1908, the inhabitants of Eastern Siberia were struck by a terrifying vision - a second sun appeared in the sky. It arose suddenly and for some time eclipsed the usual daylight. This strange new “sun was moving across the sky with amazing speed. A few minutes later, shrouded in black smoke, it fell below the horizon with a wild roar. At the same moment, a huge pillar of fire shot up over the taiga and there was a roar of a monstrous explosion, which was heard hundreds and hundreds of miles away. The terrifying heat that instantly spread from the place of the explosion was so strong that even dozens of miles from the epicenter, clothes began to smolder on people. As a result of the fall of the Tunguska meteorite, 2500 sq. km (this is 15 territories of the Principality of Liechtenstein) of taiga in the Podkamennaya Tunguska river basin. Its explosion was equivalent to 60 million tons of TNT. And this despite the fact that its diameter was only 50 - 60m. If he had arrived 4 hours later, then St. Petersburg would have left horns and legs.

In Arizona, there is a crater with a diameter of 1240m and a depth of 170m.

Approximately 125 celestial bodies are considered potentially dangerous, the most dangerous is the asteroid No. 4 "Apophis", which on April 13, 2029. can crash into the ground. Its speed is 70 km / s, diameter 320 m, weight 100 billion. t.

Scientists recently discovered the asteroid 2004 VD17, which is approximately 580m in diameter and weighs 1 billion. i.e., the probability of its collision with the ground is 5 times higher, and this collision is possible as early as 2008.

Emergency and extreme situations caused by the temperature and humidity conditions of the environment.

During changes in air temperature and humidity, as well as their combinations, such sources of emergencies appear as severe frosts, extreme heat, fog, ice, dry winds, and frosts. They can cause frostbite, or hypothermia of the body, heat or sunstroke, an increase in the number of injuries and deaths from falls.

The conditions of human life depend on the ratio of temperature and humidity of the air.

Reference:In 1932 from severe frosts, the Neagar Falls froze.

Subject. Man-made emergencies

Lecture plan:

Introduction.

1. Emergencies caused by traffic accidents.

2. Emergencies caused by fires and explosions at economic facilities

3. Emergencies caused by the release of chemically hazardous substances.

4. Emergencies associated with the release of radioactive substances.

5. Emergency situations caused by hydrodynamic accidents.

Educational literature:

1. Protection of the population and economic facilities in emergency situations

Radiation safety, part 1.

2. Protection of the population and territory in emergency situations

ed. V.G.Shakhov, ed. 2002

3. Emergencies and rules of behavior of the population in case of their occurrence

ed. V.N.Kovalev, M.V.Samoylov, N.P.Kokhno, ed. 1995

The source of a man-made emergency is a dangerous man-made incident, as a result of which a man-made emergency occurred at an object, a certain territory or water area.

Man-made emergency- this is an unfavorable situation in a certain territory that has developed as a result of an accident, a catastrophe that can cause or has caused human casualties, damage to human health, the environment, significant material losses and disruption of people's livelihoods.

Hazardous man-made incidents include accidents and catastrophes at industrial facilities or transport, fire, explosion or release of various types of energy.

Basic concepts and definitions according to GOST 22.00.05-97

Accident- this is a dangerous man-made incident that creates a threat to life and health of people at an object, a certain territory or water area and leads to the destruction of buildings, structures, equipment and vehicles, disruption of the production or transport process, as well as damage to the natural environment.

Catastrophe- This is a major accident, usually with human casualties.

man-made danger- this is a state inherent in a technical system, an industrial or transport facility that has energy. The release of this energy in the form of a damaging factor can cause damage to a person and the environment.

industrial accident- an accident at an industrial facility, technical system or industrial environment.

industrial disaster- a major industrial accident that caused loss of life, damage to human health, or destruction and destruction of an object, material assets of significant size, and also led to serious damage to the environment

2.1. Impact of small cosmic bodies

(see annex 4).

Now, 160 craters have been identified on the surface of the Earth, which arose from a collision with cosmic bodies. Here are six of the most notable:

50 thousand years ago, Berringer crater (Arizona, USA), circumference 1230 m - from a meteorite fall with a diameter of 50 m. This is the very first meteorite fall crater discovered on Earth. It was called "meteorite". In addition, it has been preserved better than others.

35 million years ago, Chesapeake Bay crater (Maryland, USA), circumference 85 km - from the fall of a meteorite with a diameter of 2-3 km. The catastrophe that created it shattered the rock base 2 km deep, creating a reservoir of salt water, which to this day affects the distribution of underground water flows.

37.5 million years ago, Popigai crater (Siberia, Russia), circumference 100 km - from the fall of an asteroid 5 km in diameter. The crater is strewn with industrial

diamonds, which arose as a result of exposure to monstrous pressures on graphite upon impact.

65 million years ago, Chicxulub basin (Yucatan, Mexico), circumference 175 km - from the fall of an asteroid with a diameter of 10 km. It is assumed that the explosion

of this asteroid caused tremendous tsunamis and earthquakes of magnitude 10.

1.85 billion years ago, Sudbury crater (Ontario, Canada), circumference 248 km - from the fall of a comet with a diameter of 10 km. At the bottom of the crater, thanks to the heat,

released during the explosion, and the water reserves contained in the comet, a system of hot springs arose. Along the perimeter of the crater, the world's largest deposits of nickel and copper ore were found.

2 billion years ago, Vredefort dome (South Africa), circumference 378 km - from the fall of a meteorite with a diameter of 10 km. The oldest and (at the time of the disaster) the largest of these craters on Earth. It arose as a result of the most massive release of energy in the entire history of our planet.

Admittedly, the most impressive discoveries of recent years in the field of paleoclimatology have been made during the drilling of ice sheets and ice core studies in the central regions of Greenland and Antarctica, where the ice surface almost never melts, which means that the information contained in it about the temperature of the surface layer of the atmosphere is stored on century. The joint efforts of Russian, French and American scientists on the isotopic composition of the ice core from an ultra-deep ice well (3350m) at the Russian Antarctic station Vostok managed to recreate the climate of our planet for this period. So, the average temperature in the area of the Vostok station for these 420 thousand years fluctuated from about - 54 to - 77 ° C. Thirdly, during the last "Ice Age" (20 - 10 thousand years ago), the climate in the middle lane Russia, including Siberia, differed little from today, especially in summer. This is evidenced by the isotopic marker of atmospheric precipitation, which has been preserved for hundreds of thousands of years in the ice of polar glaciers and in permafrost, soil carbonates, phosphates of mammalian bones, tree rings, etc. The main danger on a global scale is represented by asteroids with a radius greater than 1 km. Collision with smaller bodies can cause significant local destruction (Tunguska phenomenon), but does not lead to global consequences. The larger the asteroid, the less likely it is to hit the Earth.

The nature of the processes accompanying the fall to Earth of a round asteroid with a diameter of 10 km (that is, the size of Everest). Let us take 20 km/s as the speed of the asteroid falling. Knowing the density of the asteroid, one can find the collision energy using the formula E=M·v2/2, where M=Pi·D3·ro/6 (4), ro is the density of the asteroid, m, v and D are its mass, velocity and diameter. Densities of cosmic bodies can vary from 1500 kg/m3 for cometary nuclei to 7000 kg/m3 for iron meteorites. Asteroids have an iron-stony composition (different for different groups). It can be taken as the density of the falling body. ro~5000 kg/m3. Then the collision energy will be E ~ 5 1023 J. In TNT equivalent (an explosion of 1 kg of TNT releases 4.2 106 J of energy) this will be ~ 1.2 108 Mt. The most powerful of the thermonuclear bombs tested by mankind, ~100 Mt, had a million times less power.

Table. Energy scales of natural phenomena.

Formation of explosive meteorite craters in a layered target (see Appendix 5):

a) The beginning of penetration of the impactor into the target, accompanied by the formation of a spherical shock wave propagating downwards;

c) further formation of the transition crater funnel, the shock wave attenuates, the bottom of the crater is lined with shock melt, a continuous curtain of ejecta spreads outward from the crater;

d) the end of the excavation stage, the growth of the funnel stops. The modification stage proceeds differently for small and large craters.

In small craters, non-cohesive wall material—impact melt and crushed rocks—slips into a deep crater. When mixed, they form an impact breccia.

For large-diameter transition funnels, gravity begins to play a role - due to gravitational instability, the crater bottom bulges upwards with the formation of a central uplift.

2.1.1. Short-term consequences of the collision

As already mentioned, the work is striking in its elegance, meticulous attention to detail, so it is especially a pity that it has nothing to do with reality.

Secondly, over the past 420 thousand years, the average annual temperature of the Antarctic ice sheet has not risen above minus 54 0 C, and the shield has never disappeared during this entire period.

Joint efforts of Russian, French and American scientists on the isotopic composition of ice core from an ultra-deep ice hole (3350 m) at the Russian Antarctic station "Vostok"

managed to recreate the climate of our planet during this period. So, the average temperature in the area of the station "Vostok" for these 420 thousand years fluctuated from about - 54 to - 77 ° C.

2.2 Impact of the Sun on the Earth

From March 7 to March 29, solar activity is higher than usual and from March 7 to 29 in the Asia-Pacific, Indian regions, earthquakes do not stop (AT. region - magnitude from 4, and region - magnitude from 3).

Conclusion

As a result of viewing the literature available on the topic and on the basis of the goals and objectives set, several conclusions can be drawn.

Radiation belts play an important role in interaction with the Earth. Thanks to the belts, the Earth's magnetic field holds charged particles, namely: protons, alpha particles and electrons.

Small cosmic bodies are an equally important factor in the interaction of the Space-Earth system. It is worth considering that a large asteroid falling into the ocean will raise a destructive wave that will circle the globe several times, sweeping away everything in its path. If an asteroid hits the mainland, then a layer of dust will rise into the atmosphere, which will block sunlight. There will be an effect of the so-called nuclear winter.

Thus, space processes are the determining factor in the interaction of the "Space - Earth" system. Also, it is important that in the absence of the above phenomena, life on the planet could not exist.

Literature

1. Gnibidenko, Z.N./Z.N. Gnibidenko//Paleomagnetism of the Cenozoic of the West Siberian Plate/Geo. - Novosibirsk, 2006. - S. 146-161

2. Sorokhtin, O.V. / O.V. Sorokhtin // Theory of the Earth's development: origin, evolution and tragic future / RANS. - M., 2010. - P. 722-751

3. Krivolutsky, A. E./A. E. Krivolutsky // Blue Planet / Thought. - M., 1985.- P.326-332

4. Byalko, A. V./ A. V. Byalko // Our planet is the Earth / Science. - M., 1989.- P.237

5. Khain, V. E./ V. E. Khain// Planet Earth/ Moscow State University Geol. fak. - M., 2007.- S.234-243

6. Leonov, E.A./ E.A. Leonov// Space and super-long hydrological forecast/ Science. - M., 2010

7. Romashov, A.N./ A.N. Romashov // Planet Earth: Tectonophysics and evolution / Editorial URSS - M., 2003

8. Todhunter, I./I. Todhunter//History of mathematical theories of attraction and the figure of the Earth from Newton to Laplace/Editorial URSS. – M., 2002.- P.670

9. Vernov S.N. Radiation belts of the Earth and cosmic rays/S. N. Vernov, P. V. Vakulov, E. V. Gorchakov, Yu. I. Logachev.-M.: Education, 1970.- P.131

10. Hess W./W. Hess//The radiation belt and the Earth's magnetosphere/Atomizdat.-M., 1973.-S.423

11. Roederer X./ X. Roederer// Dynamics of radiation captured by the geomagnetic field/ Mir. - M, 1972. - S. 392

12. URL: http://dic.academic.ru/pictures/wiki/files/77/Magnetosphere_rendition.jpg

13. URL: http://www.glubinnaya.info/science/sun/sun.files/fig-1000.jpg

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15. URL: http://travel.spotcoolstuff.com/wp-content/uploads/2009/08/barringer-crater-2.jpg

16. URL: http://www.meteorite.narod.ru/proba/stati/stati58.htm

17. URL: http://att-vesti.narod.ru/KATASTR.PDF

18. URL: http://www.meteorite.narod.ru/proba/stati/stati51.htm

19. URL: http://crydee.sai.msu.ru/Universe_and_us/1num/v1pap4.htm

20. URL: http://www.tesis.lebedev.ru/sun_flares.html

A.G. Zhabin, Doctor of Geological and Mineralogical Sciences

In crystals of minerals, rocks, layered strata of sediments, signs are fixed and preserved for billions of years that characterize not only the evolution of the Earth itself, but also its interaction with space.

Terrestrial and cosmic phenomena.

In geological objects, in the language of physical and chemical properties, a kind of genetic information about the impact of cosmic processes on the Earth is recorded. Speaking about the method of extracting this information, the famous Swedish astrophysicist H. Alven states the following:

“Because no one can know what happened 45 billion years ago, we are forced to start with the present state of the solar system and, step by step, reconstruct more and more earlier stages of its development. This principle, which highlights unobservable phenomena, lies in the basis of the modern approach to the study of the geological evolution of the Earth; its motto: "the present is the key to the past."

In fact, it is already possible to qualitatively diagnose many types of external cosmic influence on the Earth. Its collision with giant meteorites is evidenced by astroblems on the earth's surface (Earth and Universe, 1975, 6, pp. 13-17.-Ed.), the appearance of denser types of minerals, the displacement and melting of various rocks. Cosmic dust and penetrating cosmic particles can also be diagnosed. It is interesting to study the connection of the tectonic activity of the planet with various chrono-rhythms (temporal rhythms) caused by cosmic processes, such as solar activity, supernovae, the movement of the Sun and the Solar system in the Galaxy.

Let us discuss the question of whether it is possible to reveal cosmogenic chronorhythms in the properties of terrestrial minerals. Rhythmic and large-scale, the nature of solar activity and other cosmophysical factors covering the entire planet can serve as the basis for the planetary "benchmarks" of time. Therefore, the search and diagnostics of material traces of such chronorhythms can be considered as a new promising direction. It jointly uses isotopic (radiological), biostratigraphic (based on fossil remains of animals and plants) and cosmogenic-rhythmic methods, which will complement each other in their development. Research in this direction has already begun: astroblems have been described, layers containing cosmic dust have been discovered in salt strata, and the periodicity of crystallization of substances in caves has been established. But if in biology and biophysics new special sections of cosmorhythmology, heliobiology, biorhythmology, dendrochronology have recently appeared, then mineralogy still lags behind such studies.

periodic rhythms.

Particular attention is now being paid to the search for possible forms of fixation in minerals of the 11-year cycle of solar activity. This chronorhythm is fixed not only on modern, but also on paleoobjects in clayey-sandy sediments of the Phanerozoic, in CoIIenia algae from the Ordovician (500 million years ago), and on sections of fossil Permian (285 million years) petrified trees. We are just beginning to look for a reflection of such cosmogenic rhythm on minerals that have grown on our planet in the hypergenesis zone, that is, in the uppermost part of the earth's crust. But there is no doubt that the climatic periodicity of a cosmogenic nature will manifest itself through a different intensity of the circulation of surface and ground waters (alternating droughts and flooding), different heating of the upper layer of the earth's crust, through a change in the rate of destruction of mountains, sedimentation (Earth and Universe, 1980, 1, p. 2-6. - Ed.). And all these factors affect the earth's crust.

The most promising places for searching for signs of such cosmogenic chronorhythms are the weathering crust, karst caves, oxidation zones of sulfide deposits, salt and flysch type sediments (the latter are a layered alternation of rocks of different composition, due to the oscillatory movements of the earth's crust), the so-called ribbon clays associated with periodic melting of glaciers.

Let us give several examples of the periodicity recorded during the growth of mineral crystals. Calcite stalactites (CaCO3) from the Sauerland caves (FRG) have been well studied. It has been established that the average thickness of the layer growing on them every year is very small, only 0.0144 mm. (growth rate is approximately 1 mm in 70 years), and the total age of the stalactite is about 12,000 years. But against the background of zones, or shells, thicker zones were also found on stalactites with annual periodicity, which grew at intervals of 10 - 11 years. Another example is celestite (SgSO4) crystals up to 10 cm in size, grown in voids among the Silurian dolomites of Ohio (USA). Very fine, well-consistent zoning was found in them. The power of one pair of zones (light and dark) varies from 3 to 70 microns, but in some places where there are many thousands of such pairs, the power is more stable 7.5 - 10.6 microns. Using a microprobe, it was possible to determine that the light and dark zones differ in the value of the Sr/Ba ratio and the curve has a pulsating character (sedimentary dolomites had become completely petrified by the time they were leached and voids formed). After considering the possible reasons for the occurrence of such zoning, preference was given to the annual periodicity of crystallization conditions. Apparently, warm and hot chloride waters containing Sr and Ba (water temperature ranges from 68 to 114C) and moving upwards in the bowels of the Earth, periodically, once a year, were diluted by surface waters. As a result, fine zoning of celestite crystals could have arisen.

The study of thin-layered sphalerite crusts from Tennessee (USA), found within the Pine Point ore deposit, also showed the periodic growth of shells, or zones, on these crusts. Their thickness is about 5 - 10 microns, and thicker ones alternate through 9 - 11 thin zones. The annual periodicity in this case is explained by the fact that groundwater penetrating into the ore deposit changes the volume and composition of solutions.

Fine annual zoning is also present in agate growing in the near-surface layer of the earth's crust. In the descriptions of agates made in the last century, sometimes up to 17,000 thin layers in one inch are noted. Thus, a single zone (light and dark band) has a power of only 1.5 µm. Such a slow crystallization of agate minerals is interesting to compare with the growth of nodules in the ocean. This speed is 0.03 - 0.003 mm. per thousand years, or 30 - 3 microns. in year. Apparently, the above examples reveal a complex chain of interrelated phenomena that determine the influence of the 11-year cycle of solar activity on the growth of mineral crystals in the surface layer of the earth's crust. Probably, the change in meteorological conditions under the action of solar corpuscular radiation is manifested, in particular, in fluctuations in the watering of the upper parts of the earth's crust.

Supernova explosions.

In addition to annual and 11-year chrono-rhythms, there are single cosmogenic "benchmarks" of time. Here we mean supernova explosions. The Leningrad botanist N. V. Lovellius studied the structure of the growth rings of an 800-year-old juniper tree growing at an altitude of 3000 m on one of the slopes of the Zeravshan Range. He found periods when the growth of tree rings slowed down. These periods almost exactly fall on the years 1572 and 1604, when supernovae flashed in the sky: Tycho Brahe's supernova and Kepler's supernova. We do not yet know the geochemical and mineralogical consequences of intense cosmic ray fluxes in connection with five supernova explosions that occurred in our Galaxy over the past millennium (1006, 1054, 1572, 1604, 1667), and we are not yet able to diagnose such signs. It is important here not so much to see traces of primary cosmic rays in terrestrial minerals (something is already known here), but to find a method for determining the time intervals when cosmic rays in the past most intensively affected our planet. Such time intervals, synchronized throughout the Earth, can be compared with ubiquitous layers of known age marking stratigraphic horizons. According to astrophysicists, about ten times during the existence of the Earth, the stars closest to the Sun flared up as supernovae. Thus, nature gives us at least ten consecutive chrono-reperators, the same for the entire planet. Mineralogists will have to find traces of such cosmogenic temporal reference points in the properties of mineral crystals and the rocks they compose. An example is the lunar regolith. It reflects the history of the impact on the Moon of the solar wind, galactic cosmic rays, micrometeorites. Moreover, large cosmogenic chrono-rhythms should be more contrasting here, because the Moon does not have an atmosphere, and, therefore, cosmic influences on it are not so much distorted. The study of regolith showed that the intensity of proton radiation on the Moon from 1953 to 1963 was four times the average intensity for several previous million years.

The idea of a causal relationship between the periodicity of geological processes on Earth and the periodicity of the interaction between the Earth and the Cosmos is increasingly penetrating the minds of geologists and planetary scientists. Now it has become clear that the periodization of geological history, geochronology is connected with solar activity by the unity of the temporal structure. But recently new data has been received. It turned out that the planetary tectono-magmatic (mineralogical) epochs correlate with the duration of the galactic year. For example, for the post-Archaean time, nine maxima of mineral matter deposition were established. They took place approximately 115, 355, 530, 750, 980, 1150, 1365, 1550 and 1780 million years ago. The intervals between these maxima are 170 - 240 million years (average 200 million years), that is, they are equal to the duration of the galactic year.

Corresponding Member of the USSR Academy of Sciences G. L. Pospelov, analyzing the place of geology in natural science, noted that the study of multistage geological complexes will lead this science to the discovery of phenomena such as "quantization" of various processes in the macrocosm. Mineralogists, together with geologists-stratigraphers, astrogeologists, astrophysicists, collect facts that in the future will make it possible to compile a time scale common to all planets in the solar system.

Schematic section of a layered area of the earth's crust. Exposed (left) and "blind" (right) hydrothermal veins are visible (thick black lines). In the left, there is an exchange of hydrotherms with surface groundwater.

1, 2, 3, 4 - successive stages of growth of minerals: quartz and pyrite crystals. The growth of crystals in the bowels of the Earth turns out to be associated with an 11-year cycle of solar activity.

Among the natural phenomena that affect the geological environment and the geographical shell, an important role is played by cosmic processes. They are caused by incoming energy and matter falling on cosmic bodies of different sizes - meteorites, asteroids and comets.

space radiation

A powerful stream of cosmic radiation directed towards the Earth from all sides of the Universe has always existed. “The outer face of the Earth and the life that fills it are the result of a versatile interaction of cosmic forces ... Organic life is only possible where there is free access to cosmic radiation, for to live means to pass through oneself the flow of cosmic radiation in its kinetic form,” considered the creator of heliobiology A. L. Chizhevsky (1973).

At present, many biological phenomena of the geological past of the Earth are considered as global and synchronous. Living systems are affected by an external source of energy - cosmic radiation, the action of which was constant, but uneven, subject to sharp fluctuations, up to the strongest, expressed in the form of impact action. This is due to the fact that the Earth, like everything else, revolving around the center of the Galaxy in the so-called galactic orbit (the time of a complete revolution is called a galactic year and it is equal to 215-220 million years), periodically fell into the zone of action of jet streams (the jet outflow of space substances). During these periods, the fluxes of cosmic radiation that hit the Earth increased, and the number of space aliens - comets and asteroids - increased. Cosmic radiation played a leading role during the explosive periods of evolution at the dawn of life. Thanks to cosmic energy, conditions were created for the emergence of the mechanism of cellular organisms. The role of cosmic radiation at the turn of the Cryptozoic and Phanerozoic during the "population explosion" is important. Today, one can speak more or less confidently about the decreasing role of cosmic radiation in the course of geological history. This is due to the fact that either the Earth is in the “favorable” part of the galactic orbit, or it has some protective mechanisms. In early geological epochs, the flow of cosmic radiation was more intense. This is expressed by the greatest "tolerance" to cosmic radiation of prokaryotes and the first unicellular organisms, and mainly blue-green algae. So, cyanides were found even on the inner walls of nuclear reactors, and high radiation did not affect their life in any way. The impact of hard short-wave and ultra-short-wave irradiation on organisms with different genetic structure, level of organization and protective properties was selective. Therefore, the impact of cosmic radiation can explain both mass extinctions and a significant renewal of the organic world at certain stages of geological history. Not without the participation of cosmic radiation, the ozone screen arose, which played a decisive role in the further direction of the earth's evolution.

Cosmogeological processes

Cosmogeological processes are associated with the fall of cosmic bodies - meteorites, asteroids and comets - to the Earth. This led to the emergence of impact, impact-explosive craters and astroblems on the earth's surface, as well as to the impact-metamorphic (shock) transformation of rock matter in the places where cosmic bodies fell.

Impact craters formed as a result of meteorite impacts are less than 100 m in diameter, impact craters, as a rule, are over 100 m. space bodies, the size of which is much larger than the size of meteorites. Astroblems found on Earth range from 2 to 300 km across.

At present, a little over 200 astroblems have been found on all continents. A much larger number of astroblems rest at the bottom of the oceans.

They are difficult to detect and inaccessible for visual study. On the territory of Russia, one of the largest is the Popigai astrobleme, located in the north of Siberia and reaching 100 km in diameter.

Asteroids are the bodies of the solar system with a diameter of 1 to 1000 km. Their orbits are between those of Mars and Jupiter. This is the so-called asteroid belt. Some asteroids orbit close to Earth. Comets are celestial bodies moving in highly elongated orbits. The central brightest part of a comet is called the nucleus. Its diameter ranges from 0.5 to 50 km. The mass of the nucleus, consisting of ice - a conglomerate of frozen gases, mainly ammonia, and dust particles, is 10 14 -10 20 g. The comet's tail consists of gas ions and dust particles escaping from the nucleus under the action of sunlight. The length of the tail can reach tens of millions of kilometers in length. Comet nuclei are located outside the orbit of Pluto in the so-called cometary Oort clouds.

While after the fall of asteroids original craters - astroblems remain, after the fall of comets craters do not appear, and their huge energy and matter are redistributed in a peculiar way.

When a cosmic body - a meteorite or an asteroid - falls, in a very short instant, within only 0.1 s, a huge amount of energy is released, which is spent on compression, crushing, melting and evaporation of rocks at the point of contact with the surface. As a result of the impact of a shock wave, rocks are formed that have the general name of impactites, and the structures that arise in this case are called impact.

Comets flying close to the Earth are attracted by gravity, but do not reach the earth's surface. They break up in the upper parts and send a powerful shock wave to the earth's surface (according to various estimates, it is 10 21 -10 24 J), which brings severe destruction that changes the natural environment, and the substance in the form of gases, water and dust is distributed over the earth's surface.

Signs of cosmogenic structures

Cosmogenic structures can be distinguished on the basis of morphostructural, mineralogical-petrographic, geophysical and geochemical features.

The morphostructural features include a characteristic ring or oval crater shape, clearly visible on space and aerial photographs and distinguished upon careful examination of the topographic map. In addition, oval shapes are accompanied by the presence of an annular swell, a central rise, and a distinct radial-annular arrangement of discontinuities.

Mineralogical and petrographic features are distinguished on the basis of the presence in impact-metamorphic craters of high-pressure modifications of minerals and minerals with impact structures of impactites, crushed and brecciated rocks.

High-pressure minerals include polymorphic modifications of SiO 2 - coesite and stishovite, small diamond crystals, morphologically different from kimberlite diamonds, and the most high-pressure modifications of carbon - lonsdaleite. They arise in the deep parts of the earth's interior, in the mantle at ultrahigh pressures, and are not characteristic of the earth's crust. Therefore, the presence of these minerals in craters gives full grounds to consider their origin to be impact.

In the rock-forming and accessory minerals of the crater, such as quartz, feldspars, zircon, etc., planar structures, or deformation lamellae, are formed - thin cracks of several microns, usually located parallel to certain crystallographic axes of mineral grains. Minerals with planar structures are called shock minerals.

Impactites are represented by melted glasses, often with fragments of various minerals and rocks. They are subdivided into tuff-like - suevites and massive lava-like - tagamites.

Among the brecciated rocks, there are: authigenic breccia - an intensely fractured rock, often processed by crushing to a state of flour; allogeneic breccia, consisting of large displaced fragments of various rocks.

Geophysical signs of cosmogenic structures are ring anomalies of gravitational and magnetic fields. The center of the crater usually corresponds to negative or reduced magnetic fields, gravitational minima, sometimes complicated by local maxima.

Geochemical features are determined by the enrichment in heavy metals (Pt, Os, Ir, Co, Cr, Ni) of the analyzed rocks of craters or astroblems. These are typical for chondrites. But, in addition, the presence of impact structures can be diagnosed by isotope anomalies of carbon and oxygen, which differ significantly from rocks formed under terrestrial conditions.

Scenarios for the formation of cosmogenic structures and the reality of cosmic catastrophes

One of the scenarios for the formation of cosmogenic structures was proposed by B. A. Ivanov and A. T. Bazilevsky.

Approaching the surface of the Earth, the cosmic body collides with it. A shock wave propagates from the point of impact, setting the matter in motion at the point of impact. The cavity of the future crater begins to grow. Partly due to the ejection, and partly due to the transformation and extrusion of collapsing rocks, the cavity reaches its maximum Depth. A temporary crater is formed. With a small size of the cosmic body, the crater may be stable. In another case, the destroyed material slides off the sides of the temporary crater and fills the bottom. A "true crater" is forming.

In a large-scale impact event, a rapid loss of stability occurs, leading to a rapid uplift of the crater bottom, collapse and lowering of its peripheral parts. In this case, a “central hill” is formed, and the annular depression is filled with a mixture of fragments and an impact melt.

In the history of the Earth, the organic world has repeatedly experienced upheavals, as a result of which mass extinctions occurred. For relatively short periods of time, a significant number of genera, families, orders, and sometimes even classes of animals and plants that once flourished disappeared. There are at least seven most significant extinctions in the Phanerozoic (the end of the Ordovician, the border of the Famennian and the Frasnian in the late Devonian, at the turn of the Permian and Triassic, at the end of the Triassic, at the border of the Cretaceous and Paleogene, at the end of the Eocene, at the turn of the Pleistocene and Holocene). Their onset and existing periodicity have been repeatedly tried to be explained by many independent reasons. Researchers today are convinced that biotic changes during an extinction event are difficult to explain by intrinsic biological causes alone. An increasing number of facts indicate that the evolution of the organic world is not an autonomous process and the environment of life is not a passive background against which this process develops. Fluctuations in the physical parameters of the environment, its unfavorable changes for life, are the direct source of the causes of mass extinctions.

The most popular are such hypotheses of extinction: exposure as a result of the decay of radioactive elements; exposure to chemical elements and compounds; thermal effect or action of the Cosmos. Among the latter are a supernova explosion in the Sun's "nearest neighborhood" and "meteorite showers". In recent decades, the hypothesis of "asteroid" catastrophes and the hypothesis of "meteorite showers" have gained great popularity.

For many years it was believed that the fall of comets on the Earth's surface is a rather rare phenomenon, occurring once every 40 - 60 million years. But recently, based on the galactic hypothesis put forward by A. A. Barenbaum and N. A. Yasamanov, it has been shown that comets and asteroids fell on our planet quite often. Moreover, they not only corrected the number of living beings and modified natural conditions, but also introduced the substance necessary for life. In particular, it is assumed that the volume of the hydrosphere almost completely depended on the cometary material.

In 1979, the American scientists L. Alvarez and W. Alvarez put forward an original impact hypothesis. Based on the discovery in Northern Italy of an increased content of iridium in a thin layer on the border of the Cretaceous and Paleogene, undoubtedly of cosmic origin, they suggested that at that time the Earth collided with a relatively large (at least 10 km in diameter) cosmic body - an asteroid. As a result of the impact, the temperatures of the surface layers of the atmosphere changed, strong waves arose - tsunamis that hit the shores, and ocean water evaporated. This was due to the fact that the asteroid, upon entering the earth's atmosphere, split into several parts. Some of the Fragments fell on land, while others sank into the waters of the ocean.

This hypothesis stimulated the study of the boundary layers of the Cretaceous and Paleogene. By 1992, the iridium anomaly had been detected at more than 105 sites on different continents and in cores from boreholes in the oceans. In the same boundary layers, microspheres of minerals formed as a result of the explosion, detrital grains of shock quartz, isotope-geochemical anomalies of 13 C and 18 O, boundary layers enriched in Pt, Os, Ni, Cr, and Au, which are characteristic of chondrite meteorites, were found. In the boundary layers, in addition, the presence of soot was detected, which is evidence of forest fires caused by an increased influx of energy during the asteroid explosion.

Currently, there is evidence that at the border of the Cretaceous and Paleogene, not only fragments of a large asteroid fell, but also a swarm of fireballs arose, which gave rise to a series of craters. One of these craters was found in the Northern Black Sea region, the other - in the Polar Urals. But the largest impact structure resulting from this bombardment is the buried Chicxulup crater in the north of the Yucatan Peninsula in Mexico. It has a diameter of 180 km and a depth of about 15 km.

This crater was discovered during drilling and contoured by gravity and magnetic anomalies. The well core contains brecciated rocks, impact glasses, shock quartz and feldspar. Emissions from this crater have been found at a far distance - on the island of Haiti and in Northeast Mexico. On the border of the Cretaceous and Paleogene, tektites were found - spheres of fused glass, which were diagnosed as formations ejected from the Chiksulupsky crater.

The second crater that arose as a result of space bombardment at the turn of the Cretaceous and Paleogene is the Kara astrobleme, located on the eastern slope of the Polar Urals and the Pai-Khoi ridge. It reaches 140 km across. Another crater was discovered on the shelf of the Kara Sea (Ust-Kara astrobleme). It is assumed that a large part of the asteroid also fell into the Barents Sea. It caused an unusually high wave - a tsunami, evaporated a significant part of the ocean water and caused large forest fires in the expanses of Siberia and North America.

Although the volcanic hypothesis puts forward alternative causes of extinction, it, unlike the impact hypothesis, cannot explain the mass extinctions that occurred in other segments of geological history. The failure of the volcanic hypothesis is revealed by comparing the epochs of active volcanic activity with the stages of development of the organic world. It turned out that during the largest volcanic eruptions, the species and genus diversity was almost completely preserved. According to this hypothesis, it is believed that massive outpourings of basalts on the Deccan Plateau in India at the turn of the Cretaceous and Paleogene could lead to consequences similar to the consequences of an asteroid or comet fall. On a much larger scale, trap eruptions occurred in the Permian period on the Siberian platform and in the Triassic on the South American platform, but they did not cause mass extinctions.

The intensification of volcanic activity can lead and has more than once led to global warming due to the release of greenhouse gases into the atmosphere - carbon dioxide and water vapor. But at the same time, volcanic eruptions also emit nitrogen oxides, which lead to the destruction of the ozone layer. However, volcanism is not able to explain such features of the boundary layer as a sharp increase in iridium, which is undoubtedly of cosmic origin, the appearance of shock minerals and tektites.

This not only makes the impact hypothesis more preferable, but also suggests that the outpouring of traps on the Deccan Plateau could even be provoked by the fall of cosmic bodies due to the transfer of energy that was introduced by the asteroid.

The study of Phanerozoic deposits has shown that in almost all boundary layers corresponding in time to the known Phanerozoic extinctions, the presence of an increased amount of iridium, shock quartz, and shock feldspar has been established. This gives reason to believe that the fall of cosmic bodies in these epochs, as well as at the turn of the Cretaceous and Paleogene, could cause mass extinctions.

The last major catastrophe in the recent history of the Earth, possibly caused by the collision of the Earth with a comet, is the Flood described in the Old Testament. In 1991, Austrian scientists, the spouses Edith Christian-Tolman and Alexander Tolman, even established the exact date of the event - September 25, 9545 BC, using tree rings, a sharp increase in the acid content in the Greenland ice sheet and other sources. e. One of the evidence for the connection of the Flood with cosmic bombardment is the rainfall from tektites over a vast area covering Asia, Australia, South India and Madagascar. The age of the tektite-bearing layers is 10,000 years, which coincides with the dating of the Tolman spouses.

Apparently, the main debris of the comet fell into the ocean, which caused catastrophic earthquakes, eruptions, tsunamis, hurricanes, global rainstorms, a sharp increase in temperature, forest fires, a general blackout from the mass of dust thrown into the atmosphere, and then a cold snap. Thus, a phenomenon now known as "asteroid winter" could have occurred, similar in its consequences to the "nuclear" winter. As a result, many representatives of the terrestrial fauna and flora of the historical past have disappeared. This is especially true for large mammals. Marine biota and small terrestrial fauna survived, being the most adapted to habitat conditions and able to hide for some time from unfavorable conditions. Primitive people were among the latter.

The Earth is an open system, and therefore it is strongly affected by cosmic bodies and cosmic processes. With the fall of cosmic bodies, the emergence on Earth of peculiar cosmogeological processes and cosmogeological structures is associated. After the fall of meteorites and asteroids on the earth's surface, explosive craters - astroblems remain, while after the fall of comets, energy and matter are redistributed in a peculiar way. The fall of comets or their passage in the immediate vicinity of the Earth are recorded in geological history in the form of mass extinctions. The largest extinction in the organic world at the turn of the Mesozoic and Cenozoic was most likely due to the fall of a large asteroid.

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space radiation

Cosmogeological processes

Signs of cosmogenic structures

Scenarios for the formation of cosmogenic structures and the reality of cosmic catastrophes

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