Therefore, in everyday life the magnitude value is called Richter scale.

Earthquake magnitude and earthquake intensity rating scale

The Richter scale contains conventional units (from 1 to 9.5) - magnitudes, which are calculated from vibrations recorded by a seismograph. This scale is often confused with earthquake intensity scale in points(according to a 7 or 12-point system), which is based on the external manifestations of an earthquake (impact on people, objects, buildings, natural objects). When an earthquake occurs, it is its magnitude that first becomes known, which is determined from seismograms, and not its intensity, which becomes clear only after some time, after receiving information about the consequences.

Correct usage: « magnitude 6.0 earthquake».

Previous use: « earthquake measuring 6.0 on the Richter scale».

Misuse: « magnitude 6 earthquake», « earthquake measuring 6 magnitudes on the Richter scale» .

Richter scale

$M\_s\; =\; \backslash lg\; (A/T)\; +\; 1.66\; \backslash lg\; D\; +\; 3.30.$

These scales do not work well for the largest earthquakes - when M~8 comes saturation.

Seismic moment and Kanamori scale

The seismic energy released by a nuclear explosion with a power of 1 megaton (1 megaton = 4.184 10 15 J) is equivalent to an earthquake with a magnitude of about 7. It is worth noting that only a small part of the explosion energy is converted into seismic vibrations.

Frequency of earthquakes of different magnitudes

In a year on Earth, approximately:

• 1 earthquake with a magnitude of 8.0 or higher;
• 10 - with a magnitude of 7.0-7.9;
• 100 - with a magnitude of 6.0-6.9;
• 1000 - with a magnitude of 5.0-5.9.

The strongest recorded earthquake occurred in Chile in 1960—later estimates put Kanamori's magnitude at 9.5.

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An excerpt characterizing the magnitude of the earthquake

The historical sea, not as before, was directed by gusts from one shore to another: it seethed in the depths. Historical figures, not as before, rushed in waves from one shore to another; now they seemed to be spinning in one place. Historical figures, who previously at the head of the troops reflected the movement of the masses with orders of wars, campaigns, battles, now reflected the seething movement with political and diplomatic considerations, laws, treatises...
Historians call this activity of historical figures reaction.
Describing the activities of these historical figures, who, in their opinion, were the cause of what they call the reaction, historians strictly condemn them. All famous people of that time, from Alexander and Napoleon to m me Stael, Photius, Schelling, Fichte, Chateaubriand, etc., are subject to their strict judgment and are acquitted or condemned, depending on whether they contributed to progress or reaction.
In Russia, according to their description, a reaction also took place during this period of time, and the main culprit of this reaction was Alexander I - the same Alexander I who, according to their descriptions, was the main culprit of the liberal initiatives of his reign and the salvation of Russia.
In real Russian literature, from a high school student to a learned historian, there is not a person who would not throw his own pebble at Alexander I for his wrong actions during this period of his reign.
“He should have done this and that. In this case he acted well, in this case he acted badly. He behaved well at the beginning of his reign and during the 12th year; but he acted badly by giving a constitution to Poland, making the Holy Alliance, giving power to Arakcheev, encouraging Golitsyn and mysticism, then encouraging Shishkov and Photius. He did something wrong by being involved in the front part of the army; he acted badly by distributing the Semyonovsky regiment, etc.”
It would be necessary to fill ten pages in order to list all the reproaches that historians make to him on the basis of the knowledge of the good of humanity that they possess.
What do these reproaches mean?
The very actions for which historians approve of Alexander I, such as: the liberal initiatives of his reign, the fight against Napoleon, the firmness he showed in the 12th year, and the campaign of the 13th year, do not stem from the same sources - the conditions of blood , education, life, which made Alexander’s personality what it was - from which flow those actions for which historians blame him, such as: the Holy Alliance, the restoration of Poland, the reaction of the 20s?
What is the essence of these reproaches?
The fact that such a historical person as Alexander I, a person who stood at the highest possible level of human power, is, as it were, in the focus of the blinding light of all the historical rays concentrated on him; a person subject to those strongest influences in the world of intrigue, deception, flattery, self-delusion, which are inseparable from power; a face that felt, every minute of its life, responsibility for everything that happened in Europe, and a face that is not fictitious, but living, like every person, with its own personal habits, passions, aspirations for goodness, beauty, truth - that this face , fifty years ago, not only was he not virtuous (historians do not blame him for this), but he did not have those views for the good of humanity that a professor now has, who has been engaged in science from a young age, that is, reading books, lectures and copying these books and lectures in one notebook.
But even if we assume that Alexander I fifty years ago was wrong in his view of what the good of peoples is, we must involuntarily assume that the historian judging Alexander, in the same way, after some time will turn out to be unjust in his view of that , which is the good of humanity. This assumption is all the more natural and necessary because, following the development of history, we see that every year, with every new writer, the view of what is the good of humanity changes; so that what seemed good appears after ten years as evil; and vice versa. Moreover, at the same time we find in history completely opposite views on what was evil and what was good: some take credit for the constitution given to Poland and the Holy Alliance, others as a reproach to Alexander.
It cannot be said about the activities of Alexander and Napoleon that they were useful or harmful, because we cannot say for what they are useful and for what they are harmful. If someone does not like this activity, then he does not like it only because it does not coincide with his limited understanding of what is good. Does it seem good to me to preserve my father’s house in Moscow in 12, or the glory of the Russian troops, or the prosperity of St. Petersburg and other universities, or the freedom of Poland, or the power of Russia, or the balance of Europe, or a certain kind of European enlightenment - progress, I must admit that the activity of every historical figure had, in addition to these goals, other, more general goals that were inaccessible to me.
But let us assume that so-called science has the ability to reconcile all contradictions and has an unchanging measure of good and bad for historical persons and events.
Let's assume that Alexander could have done everything differently. Let us assume that he could, according to the instructions of those who accuse him, those who profess knowledge of the ultimate goal of the movement of mankind, order according to the program of nationality, freedom, equality and progress (there seems to be no other) that his current accusers would have given him. Let us assume that this program was possible and drawn up and that Alexander would act according to it. What would then happen to the activities of all those people who opposed the then direction of the government - with activities that, according to historians, were good and useful? This activity would not exist; there would be no life; nothing would have happened.

Richter scale was invented to determine the strength of earth vibrations. In other words, it will help us determine the power of earthquakes. This system is international. It was invented by the Italian Mercalli. Who was Richter and why did he get all the laurels?

History of the Richter scale

Richter earthquake scale developed in the thirties of the twentieth century. The Mercalli system was not only renamed, but also completed. The Italian used a 12-point scale as a basis. The minimum tremors were equal to one.

Earthquakes of magnitude 6 and above were considered strong. Not all states agreed with this. , for example, they used a 10-point scale, and in Japan a 7-point scale. But in the age of globalization, everything has changed.

A common standard was needed, and the data from all seismographs could be deciphered anywhere on Earth. This is where Charles Richter got down to business. The American began to use the decimal logarithm.

The measurement of the amplitude of the oscillations was directly proportional to the change in the needle on the seismograph. Richter also made adjustments depending on the distance of the area from the epicenter of the earthquake.

Richter magnitude scale was officially registered in 1935. The world began to focus not only on 10 points, but also on the difference of ten points between adjacent marks on the ruler.

A 2-magnitude earthquake is considered 10 times stronger than a 1-magnitude one, and 3-magnitude tremors are 10 times more powerful than 2-magnitude ones, and so on. But how to determine the strength of shocks? How to find out and determine that the movements of the earth’s crust are exactly 3, 7, 9-point?

Richter scale - scores in visual and physical manifestations

The scores will help us measure the frequency of surface tremors. Their power in the bowels of the Earth, where the fault occurred, is greater. Part of the energy leaves on the way to the solid crust of the planet. This means that the closer the source is to the surface, the greater the power. People don't feel one point.

Two points will be felt only by residents of the upper floors of high-rise buildings, feeling weak vibrations. At three points the chandeliers swing. Perceptible shaking inside buildings, even small ones, is four points.

And five-magnitude earthquakes are felt not only in houses, but also on the streets. At six points, glass may crack, furniture and dishes may move. It becomes difficult to stand on your feet during a magnitude 7 earthquake. Cracks spread along brick walls, flights of stairs can be destroyed, and landslides occur on roads.

With eight points, buildings can be destroyed, as well as communications located underground can be torn. Nine-magnitude tremors lead to disturbances on the water and can cause a tsunami. The soil is cracking.

It crushes and breaks it during magnitude 10 earthquakes. Eleven points... Stop. After all, the Richter scale ends at ten. That's the point. Gaps in people's knowledge led to the mixing of the Mercalli and Richter systems.

The surface intensity of the tremors was measured in points using the Italian scale. She, apparently, did not disappear, but unofficially joined the American one. Mercalli has both 11 and 12 points.

At 11, brick buildings will collapse to the ground, and roads will also remain only a memory. 12 points is a catastrophic earthquake that changes the topography of the earth. The cracks in it reach a width of 10-15 meters.

What do the marks on the true Richter scale tell us? It is based on magnitude, which Mercalli did not take into account. Magnitude measures the energy released during movements in the earth's interior. They consider not the external manifestations of an earthquake, but their internal essence.

Richter scale - magnitude table

While it is possible to determine the scores by observing changes on the surface of the planet, the magnitude is measured only using seismograph readings. The calculation is based on the type of waves of a typical, average earthquake.

The indicator is put in logarithm with the maximum amplitude of specific shocks. Magnitude is proportional to this logarithm.

The strength of the energy released during an earthquake depends on the size of its source, that is, the length and width of the fault in the rocks. Typical Richter shocks can be measured not only in whole numbers, but also in fractions.

Thus, a magnitude of 4.5 leads to minor destruction. The parameters of the fault are only a few meters vertically and in length. A source of several kilometers usually produces earthquakes with a magnitude of 6.

The fault is hundreds of kilometers long - magnitude 8.5. There is also a ten on the Richter scale. But this is, so to speak, an unrealistic limit. There have been no earthquakes on Earth with a magnitude greater than 9. Apparently it won't happen.

For magnitude 10, a fault depth of more than 100 kilometers is needed. But, at such a depth, the earth is no longer solid, the substance turns into liquid - the mantle of the planet. The length of a ten-fold outbreak should exceed 1000 kilometers. But such faults are not known to scientists.

Earthquakes with a magnitude of 1 do not occur, or rather are not recorded by instruments. The weakest tremors, felt by both seismographs and people, are 2 points. Yes, magnitude indicators are sometimes also called points. But, it is more correct to pronounce only the number, so that there is no confusion with the Mercalli scale.

There is an approximate relationship between the magnitude of an earthquake and its magnitude. At the same time, it is important to take into account the depth of the shock source. The easiest way to compare the indicators is by looking at the table.

Kilometers	Magnitude
5	5	6	7	8
10	7	8-9	10	11-12
20	6	7-8	9	10-11
40	5	6-7	8	9-10

The table shows that the same magnitude can lead to different destruction depending on the depth of the source. There are other reasons to judge what it will be like earthquake in points? Richter scale points They also depend on the seismic resistance of buildings in the area of ​​tremors and the nature of the soil.

In strong buildings, the force of an earthquake is perceived differently than in houses built without taking into account possible movements of the earth's crust. Charles Richter talked about this back in the 1930s.

The scientist not only created an international scale, but spent his entire life fighting for reasonable construction, taking into account all the risks of a particular area. It was thanks to Richter that many countries tightened building construction standards.

“Richter scale” is the common name for a scale showing the magnitude of an earthquake.

The Richter scale characterizes the energy that is released in the form of seismic waves during an earthquake. This system was proposed relatively recently - in 1935.

The Richter scale is sometimes confused with another classification that shows the level of impact of an earthquake on external objects - people, buildings, natural formations. These are actually two different scales.

The Richter system contains arbitrary units from 1 to 9.5, and the intensity scale contains 7 or 12 points. During an earthquake, only its magnitude can be determined immediately, and the intensity can be assessed later, when the consequences of the vibrations become known.

Creation of the Richter scale

The first scale to assess the intensity of an earthquake was proposed back in 1902; its creator was Giuseppe Mercalli, an Italian priest and geologist. This classification can be called scientific with a big stretch: the description of the degree of tremors is made in it on the basis of purely subjective sensations.

For example, an earthquake of magnitude II is described as “felt in a calm environment on the upper floors of buildings”; however, since then construction technologies have changed, there are many more floors, and a “calm environment” is a completely individual concept for each person.

If the house collapses, but people managed to run out, then fewer points are given, and if they died under the rubble, then more. Subsequently, Richter himself improved the Mercalli scale, and in this form it is still sometimes used - mainly in the USA. However, Richter wanted to get a truly objective and rigorous system for assessing earthquakes.

He proposed using a standard seismograph that records tremors using needle oscillations. The strength of the earthquake in the proposed system was estimated as the decimal logarithm of the needle movement, despite the fact that the seismograph is located no further than 600 km from the epicenter. The distance from the epicenter affects the accuracy of measurements, so a correction function was introduced into the equation, calculated from the table.

However, this system had its drawbacks: Richter used Southern California earthquakes, the sources of which are shallow, as the basis for calibrating his scale. The first Richter scale ended at 6.8 units, since the equipment of that time did not allow more. The method measured only surface waves, while in deep earthquakes a significant part of the energy is released in the form of body waves.

Apparently, at that time the young scientist lacked knowledge about earthquakes of various types. Long years of observation of this phenomenon made it possible to significantly rework and refine the Richter scale. Currently, several of its varieties are used, used for different cases.

Beno Gutenberg

The honor of creating the Richter scale does not belong to Richter alone. He developed it in collaboration with Beno Gutenberg, a native of Germany. Gutenberg also seriously studied earthquakes, but he was a Jew, so when the Nazis came to power he was forced to flee to the United States. There he founded a seismic laboratory, in which Richter began working with him.

- classification of earthquakes by magnitude, based on an assessment of the energy of seismic waves occurring during earthquakes. The scale was proposed in 1935 by the American seismologist Charles Richter (1900-1985), theoretically substantiated together with the American seismologist Beno Gutenberg in 1941-1945, and became widespread throughout the world.

The Richter scale characterizes the amount of energy that is released during an earthquake. Although the magnitude scale is not limited in principle, there are physical limits to the amount of energy released in the earth's crust.
The scale uses a logarithmic scale, so that each integer value on the scale indicates an earthquake ten times larger in magnitude than the previous one.

An earthquake with a magnitude of 6.0 on the Richter scale will produce 10 times more ground shaking than an earthquake with a magnitude of 5.0 on the same scale. The magnitude of an earthquake and its total energy are not the same thing. The energy released at the source of an earthquake increases by about 30 times with an increase in magnitude by one unit.
The magnitude of an earthquake is a dimensionless quantity proportional to the logarithm of the ratio of the maximum amplitudes of a certain type of waves of a given earthquake, measured by a seismograph, and some standard earthquake.
There are differences in methods for determining the magnitudes of nearby, distant, shallow (shallow) and deep earthquakes. Magnitudes determined from different types of waves differ in magnitude.

Earthquakes of different magnitudes (on the Richter scale) manifest themselves as follows:
2.0 - the weakest felt shocks;
4.5 - the weakest shocks, leading to minor damage;
6.0 - moderate damage;
8.5 - the strongest known earthquakes.

Scientists believe that earthquakes stronger than magnitude 9.0 cannot occur on Earth. It is known that each earthquake is a shock or a series of shocks that arise as a result of the displacement of rock masses along a fault. Calculations have shown that the size of the earthquake source (that is, the size of the area on which the rocks were displaced, which determines the strength of the earthquake and its energy) with weak tremors barely perceptible by humans is measured in length and vertically by several meters.

During earthquakes of medium strength, when cracks appear in stone buildings, the size of the source reaches kilometers. The sources of the most powerful, catastrophic earthquakes have a length of 500-1000 kilometers and go to a depth of 50 kilometers. The largest earthquake recorded on Earth has a focal area of ​​1000 x 100 kilometers, i.e. close to the maximum length of faults known to scientists. It is also impossible to further increase the depth of the source, since earthly matter at depths of more than 100 kilometers goes into a state close to melting.

Magnitude characterizes an earthquake as a single, global event and is not an indicator of the intensity of the earthquake felt at a specific point on the Earth's surface. The intensity or strength of an earthquake, measured in points, not only depends greatly on the distance to the source; Depending on the depth of the center and the type of rock, the strength of earthquakes with the same magnitude can differ by 2-3 points.

The intensity scale (not the Richter scale) characterizes the intensity of the earthquake (the effect of its impact on the surface), i.e. measures the damage caused to a given area. The score is established during a survey of the area based on the magnitude of destruction of ground structures or deformations of the earth's surface.

There are a large number of seismic scales, which can be reduced to three main groups. In Russia, the 12-point scale MSK-64 (Medvedev-Sponheuer-Karnik), which is the most widely used in the world, is used, dating back to the Mercalli-Cancani scale (1902), in Latin American countries the 10-point Rossi-Forel scale (1883) is adopted, in Japan - 7-point scale.

The intensity assessment, which is based on the everyday consequences of an earthquake, which are easily distinguishable even by an inexperienced observer, is different on the seismic scales of different countries. For example, in Australia, one of the degrees of shaking is compared to “the way a horse rubs against a veranda post”; in Europe, the same seismic effect is described as “bells begin to ring”; in Japan, “an overturned stone lantern” appears.

The material was prepared based on information from open sources

More than 2000 years ago, a device was created in China to warn people against an upcoming earthquake. This device was shaped like a frog, with an oval base and four inclined planes in which metal balls were placed. When an earthquake occurred, vibrations caused by seismic waves rocked the device and the balls fell out of their nests onto a metal stand. It was a warning of an approaching earthquake. Thus, from the first days of the emergence of the science of seismology, its task was to warn people about an approaching earthquake, thereby ensuring the safety of people’s lives from natural disasters. It took 2000 years for the infamous decision of an international conference in London in 1996 to appear, which stated that earthquake prediction was not possible. Does this mean that the efforts of thousands of scientists who dedicated their lives to solving this problem of humanity and billions of dollars spent on research were in vain? The fact that this decision was made by “skeptics,” as scientists are called who have lost hope of finding a positive result in the study of a specific problem, out of despair, was clear even then, because since June 1995 The press of more than 20 countries of the world reported that the Sakhalin earthquake was predicted by the author and the Russian Emergency Situations Ministry received a warning from the Armenian Emergency Situations Ministry three months before the tragedy, when the city of Neftegorsk disappeared from the face of the Earth. At the beginning of the twentieth century, changes in the ratio of longitudinal (VP) and transverse (VS) seismic waves in the zone of development of the source of strong earthquakes were first obtained. And this attitude became the first harbinger of earthquakes. Scientists in many developed countries of the world have begun to conduct research with the goal of creating earthquake forecasting technology capable of determining the location (latitude and longitude coordinates of the source), time (year, month, day) and strength (magnitude) of future earthquakes. Currently, more than 300 earthquake precursors are known, which have not led to a solution to this problem and the question of predicting earthquakes remained unanswered. What is the reason for the failure? In terms of catastrophic consequences, which lead to a huge number of casualties and destruction, earthquakes are the most dangerous natural disasters. The number of victims from earthquakes in the twentieth century was 1.4 million (Osipov, 2001), of which about 1.0 million victims occurred in the last 30 years. In the first 12 years of the 21st century, the number of deaths from earthquakes is approaching 1.0 million (about 800,000): Indonesia (about. Sumatra, 2004) - about 300,000; Haiti – about 300,000; Japan (Fukushima)…The following occur annually: 1 earthquake – with a magnitude of up to 9; about 15 earthquakes - up to 8; 140 - up to 7; 900 - up to 6; 8000 - up to 5. Currently, these numbers tend to increase. Scientists from all over the world have been and are studying the issue of predicting earthquakes, and billions of dollars have been spent on this research, but earthquakes continue to destroy cities, people, and countries. What is the reason for the helplessness of scientists from all over the world? Politicians and the Ministry of Emergency Situations are not interested in these issues, but Governments turn to them when a disaster occurs and people, cities and countries die. At the London conference in 1996. Many experts have concluded that seismic forecasting is hopeless. The results of the conference were published: “Is seismic forecasting hopeless? Complete pessimism regarding the possibility of reliable earthquake prediction was expressed by some geophysicists at an international conference held in November 1996 in London. R. Geller (University of Tokyo) noted that, despite the efforts and resources expended by the international community of scientists, over the past decades it has not been possible to detect a single reliable sign of an impending seismic event (some signals are at the noise level or even below, undue importance has been given). Seismologist S. Crampin (University of Edinburgh, Scotland) shared this opinion. Experts' skepticism increased after several Greek seismologists announced that they were allegedly able to predict earthquakes based on previous variations in the Earth's magnetic field; Strong criticism of their report pointed to completely vague information about the place and time of the upcoming tremors and their intensity. Many scientists now believe that earthquakes are generally among the critical phenomena that occur in a system brought to the brink of unstable equilibrium. Predicting specifically when a critical event will occur is almost impossible; According to seismologist I.Main (I.Main; University of Edinburgh), predicting an earthquake is as difficult as determining in advance which particular snowflake will cause an avalanche in the mountains. However, having classified tremors as a critical phenomenon, experts can now make new amendments to building codes taking into account scientific criteria for the seismic resistance of structures (existing rules are mainly based on bare empirics). New Scientist. 1996.V.152. N 2056. P.10 (Great Britain).” So, in 1996 An international conference in London, based on the opinion of R. Geller (University of Tokyo) and two employees of the University of Edinburgh, pronounced a verdict on more than a century of work by world scientists on the impossibility of determining in advance the place, time and magnitude of a future earthquake. Apparently the authors of this project were not aware that in 1995, i.e. one year before the London decision, the author of these lines developed a physical model that allows theoretical calculation of the parameters of future earthquakes on the planet: location (latitude and longitude coordinates), time (year, month and day) and strength (magnitude) for an unlimited time forward - a methodology for short-term forecasting of earthquakes and other natural disasters (Publications: 1. Forecasting earthquakes. Monograph. Increasing the seismic resistance of buildings and structures. Publishing house "Hayastan", Yerevan, 1989, chapter, 8.5, p. 316. 2. Electromagnetic model of the mechanism of occurrence source of earthquakes. "Bulletin" of the International Academy of Ecology and Life Safety, St. Petersburg, No. 7(19), 2000, 3. Pattern of connection of seismic waves emitted by the source of earthquakes. "Bulletin" of the International Academy of Ecology and Life Safety, St. St. Petersburg, No. 7(31), 2000 4. Short-term forecast of earthquakes and other natural disasters. Monograph. St. Petersburg, 2000, p. 135. 5. Earthquakes and natural disasters shorth-term prediction. St. Petersburg. 2000, p. 128). . Moscow, Russia; “Syukan Shincho”, 07/07/1995, Tokyo, Japan; London, Great Britain; Iran, “Alik” 1995; Over the past 17 years, this method has been used to calculate the parameters (location, time and magnitude) of more than 40,000 future earthquakes and other natural disasters, with an accuracy of 95%, including all disasters that occurred during this time. Short-term forecast of earthquakes using instrumental, and Moreover, the probabilistic research methods used by modern seismology are really not possible. Therefore, until now, all efforts of scientists in this area of ​​seismology have failed. How do studies conducted today differ from those used in 1996? ? Nothing, only the quantity and, possibly, quality of the equipment used has increased. Therefore, one cannot count on success in solving the problem of short-term earthquake forecasting using “modern instrumental research methods.” In this matter, the London Conference would have been more useful if the decision adopted at it had added; "modern methods of instrumental research." Short-term forecasting of earthquakes and other natural disasters is possible and exists. It is possible to predict future natural disasters with absolute accuracy for an unlimited time in advance. The method consists of two parts. 1. A theoretical calculation of the location, time and strength of future earthquakes is carried out... 2. A month before the calculated time, seismic stations of a given country conduct studies of changes in parameters of the specified region and clarify the theoretical calculation. This will allow, 3-4 days before the earthquake, to accurately indicate the location, time and strength of the future earthquake. 3. Accurate data obtained about a future earthquake, tsunami... are transferred to the Government, which will make a decision on the safety of people’s lives.