The highest magnitude earthquake on the Richter scale. earthquake scale

Earthquakes vary in strength and effects on the earth's surface. And in science, attempts have been repeatedly made to classify them according to these indicators.

As a result of such attempts, 12 point scales were developed, based on an assessment of their impact on the earth's surface.

12 point scale for assessing the intensity of earthquakes (hereinafter earthquake scale) estimates the intensity of an earthquake in points at a given point, regardless of its power at the epicenter.

Richter scale has a different approach and estimates the amount of seismic energy released at the epicenter of an earthquake. Seismic energy unit — magnitude.

12 point earthquake scale.

In 1883, 12 points earthquake scale was designed by Giuseppe Mercali. Later, it was improved by the author himself, and, later, also by Charles Richter (the author of the Richter scale) and was called the Modified Mercalli Earthquake Scale.

This earthquake scale is currently used in the United States.

In the USSR and Europe long time 12 point scale of earthquakes - MSK-64 was used. According to it, as well as according to the Mercalli earthquake scale, their intensity is measured in points indicating the intensity, nature and scale of the impact on the surface of the earth, structures, people and animals in the area.

The MSK-64 earthquake scale is very clear. And if we hear in the means mass media about the fact that there was an earthquake with a magnitude of 6 points, we can very simply imagine that, according to this scale of earthquakes, it was strong, it was felt by all people. Many of them ran out into the street. Pieces of plaster fell off, and paintings fell from the walls.

Or an earthquake of magnitude 9 can be imagined as devastating, in which stone houses were damaged and destroyed, and wooden houses squinted.

Everything is simple and clear.

At the same time, it should be noted that according to the scale of earthquakes, their intensity is estimated at a certain point. It is clear that at the epicenter, located above the source of the earthquake, and at a distant point, its intensity will be different.

In 1988, the European Seismic Committee began updating the MSK-64 earthquake scale and in 1996 an updated earthquake scale called EMS-98, together with an application guide, was recommended for use. This earthquake scale is also 12 points and has no fundamental differences with other earthquake scales.

Japan uses the Japan Meteorological Agency earthquake scale. It starts with three points, when people begin to feel points.

In it, in separate columns, the impact on people, on the situation inside buildings and on the street is described. The highest score on this earthquake scale is 7.

It also does not differ fundamentally from other scales.

Richter scale. Magnitude.

Often, including in the media, you can hear about an earthquake that happened somewhere with a force of, for example, 6 points on the Richter scale.

This is not true. The Richter scale does not describe the intensity of an earthquake, expressed in points, but a completely different characteristic, expressed in other units.

The Richter scale estimates the magnitude of the released seismic energy at the epicenter according to the amplitude of soil vibrations measured by instruments that reached the measurement point. This value is expressed in magnitude.

Richter himself defined the magnitude of any shock as: "the logarithm, expressed in microns, of the amplitude of the record of this shock, made by a standard short-period torsional seismometer at a distance of 100 kilometers from the epicenter."

Magnitude is calculated after measuring the amplitude on the seismogram. And when calculating, it is necessary to make corrections: for the depth of the earthquake source, for the fact that the measurements were carried out with a non-standard seismometer. It is necessary to bring the calculations to those measured at a standard distance of 100 km from the epicenter.

These are difficult calculations. And because of the listed difficulties, the magnitudes given by various sources may vary slightly.

But in general, they will give an objective assessment of the power of the earthquake.

Therefore, it would be correct to say that an earthquake with a magnitude of, say, -5 on the Richter scale occurred in a certain place.

Magnitude, calculated at different points on the Richter scale will have one value. The intensity of shocks in points at different points will be different.

This is the difference between the 12-point earthquake scale and the 9.5-point Richter scale, expressed in magnitude (the Richter scale has a range of 1 - 9.5 magnitude).

Do not confuse (and in the media this happens all the time) the concepts of the Richter scale and the 12-point earthquake scale.

The intensity on the Richter scale is determined immediately by the readings of seismographs. The intensity in points is determined later, according to the impact on the earth's surface. Therefore, the very first reports on estimating the power of shocks come precisely on the Richter scale.

How to correctly report the intensity of tremors in magnitude on the Richter scale?

The correct usage is "an earthquake of magnitude 7 on the Richter scale."

Previously, due to an oversight, the wrong expression was used - "an earthquake of 7 points on the Richter scale."

Or it is also not correct - “an earthquake of 7 magnitudes on the Richter scale” or “a magnitude of 7 on the Richter scale”.

The Richter scale describes the power of tremors at the epicenter, regardless of conditions, and introduces a unit of measure for the power of tremors - magnitude. Other scales describe their impact on the surface in different places depending on the conditions, soils, rocks, distance from the epicenter, etc.

For this reason Richter scale is the most objective and scientifically substantiated.

Richter scale(joke)

Richter scale created to determine the strength of the earth's vibrations. In other words, the ruler helps to establish the power of earthquakes. The system is international. The Italian Mercalli began to develop it. Who is Richter and why did he take the laurels from his predecessor? We will find out.

History of the Richter scale

Richter earthquake scale adopted in the 1930s. The Mercalli system is not just renamed, but refined. The Italian was sluggish for a 12-point basis. The minimum shocks are one.

Earthquakes from 6 points were recognized as strong. This did not suit all states. In Russia, for example, they were guided by 10, and in Japan by 7-point limits. Meanwhile, the age of globalization has arrived.

A single standard was required so that the data of all seismographs were understandable at any point on the Earth. This is where Charles Richter got involved. The American suggested using the decimal logarithm.

The calculation of the oscillation amplitude is directly proportional to the deflection of the needle on the seismograph. At the same time, Richter introduced an amendment in accordance with the remoteness of the area from the epicenter of the earthquake.

Richter magnitude scale was officially adopted in 1935. The world began to focus not just on 10 points, but also on the 10-point difference between adjacent marks on the ruler.

A 2-point earthquake is 10 times stronger than a 1-point earthquake. 3-point pushes are 10 times more powerful than 2-point pushes, and so on. But, how to determine the strength of concussions? How to understand that progress earth's crust exactly 3, 7, 9-point?

Richter scale - scores in visual and physical manifestations

The scores help measure the intensity of surface tremors. Their strength in the bowels of the Earth, where the rift occurs, is greater. Part of the energy is lost on the way to the solid crust of the planet. It turns out that the intensity is higher, the closer to the surface of the source. 1 point is not perceptible by people.

2 points are recognized only on the upper floors of skyscrapers, weak vibrations are felt. At 3 points, the chandeliers swing. Perceptible shaking inside buildings, even low-rise ones, is 4 points.

5-magnitude earthquakes are detected not only in houses, but also on the street. At 6 points, glass can burst, furniture and dishes move. It becomes difficult to stay on your feet during a 7-magnitude earthquake. By brick walls cracks spread, flights of stairs collapse, landslides form on the roads.

At 8 points, buildings are already collapsing, as well as communications laid underground. 9-magnitude tremors lead to unrest in water bodies, can cause, for example, a tsunami. The soil is cracking.

It is crushed and broken during 10-magnitude earthquakes. 11 points… Stop. After all, the Richter scale ends at ten. In fact of the matter. Gaps in the knowledge of the inhabitants led to a mixture of the systems of Mercalli and Richter.

The surface intensity of shocks in points was measured according to the Italian scale. She, apparently, has not sunk into oblivion, but unofficially joined the American one. Mercalli has both 11 and 12 points.

At 11 brick buildings collapse to the ground, from the roads, too, remains only a reminder. 12 points is a catastrophic earthquake that changes the relief of the earth. Cracks in it reach a width of 10-15 meters.

Now let's figure out what the marks of the true Richter scale say. It is "tied" to the magnitude, which Mercalli did not take into account. The magnitude determines the energy released during movements in the earth's interior. Not considered external manifestations earthquakes, but its inner essence.

Richter scale - magnitude table

If you can determine the scores by observing changes on the surface of the planet, then the magnitude is calculated only from the readings of seismographs. The calculations are based on the type of waves of some typical, averaged earthquake.

The indicator is put in the logarithm with the maximum amplitudes of specific shaking. The magnitude is proportional to this logarithm.

The strength of the energy emitted during an earthquake depends on the size of its source, that is, the length and width of the fault in the rocks. Typical shocks according to Richter can be measured not only by integers, but also by fractional numbers.

So, a magnitude of 4.5 leads to minor damage. The fault parameters are only a few meters vertically and in length. A source of several kilometers, as a rule, produces earthquakes with a magnitude of 6.

Fault hundreds of kilometers - magnitude 8.5. The Richter scale also has 10. But, this is, so to speak, an unrealistic limit. On Earth, there have been no earthquakes with a magnitude higher than 9. Apparently it won't happen.

For the 10th magnitude, 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 a liquid - the mantle of the planet. The length of the focus, pulling on the top ten, 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’s 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 correlate 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

It can be seen that the same magnitude can lead to different damage depending on the depth of the source. There are other reasons to judge what will be earthquake in points? Scores on the Richter scale also depend on the seismic resistance of buildings in the area of ​​tremors, the nature of the soil.

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

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

Why was the strength of earthquakes previously reported in points on the Richter scale, and now they began to mention some magnitudes?

As answered in the Crimean Expert Council, the magnitude is a characteristic of the energy released in the earthquake source. There are two approaches to assessing the strength of earthquakes. According to the first, the intensity of an earthquake is estimated by its manifestation and consequences on the earth's surface. The assessment is made in points on a macroseismic scale. In Ukraine and Russia, a scale from 1 to 12 points is adopted.

The international seismic 12-point scale is as follows.

1. Inconspicuous. It is noted only by seismic instruments.
2. Very weak. It is noted by individuals who are at rest.
3. Weak. It is noted only by a small part of the population.
4. Moderate. It is recognized by the slight rattling and vibration of objects, dishes, window panes, the creak of doors and windows.
5. Pretty strong. General shaking of buildings. Shaking furniture. Cracks in window panes and plaster.
6. Strong. Felt by everyone.
7. Very strong. Cracks in the walls of stone houses. Anti-seismic and wooden buildings remain unharmed.
8. Destructive. Cracks on steep slopes and on damp soil, houses are badly damaged.
9. Devastating. Severe damage and destruction of stone houses.
10. Destroying. Large cracks in the soil. Landslides and collapses. Destruction of stone buildings. Curvature of railroad tracks.
11. Disaster. Wide cracks in the ground. Numerous landslides and collapses.
12. Strong disaster. Changes in the soil reach enormous proportions. Numerous collapses, landslides, cracks. The emergence of waterfalls, ponds on lakes, changes in the course of rivers. None of the buildings survive.

The second way to assess the strength of an earthquake is to estimate the energy of the shock using the intensity scale proposed by the American seismologist Richter in 1935. This scale is built on arbitrary units - magnitudes (Latin magnitudo - magnitude).

Generally speaking, it is impossible to measure the energy of an earthquake with absolute accuracy. The seismic wave, by which we judge the magnitude of an earthquake, carries information about only fractions of a percent of the energy emitted by the source. It is extremely difficult to determine the true value of energy from it, eliminating the measurement error. Therefore, a magnitude concept was introduced - a relative scale. It is generally accepted that if an earthquake that occurred leads to soil displacements at a distance of 100 km from the epicenter equal to 1 micron, then its magnitude corresponds to magnitude 1. The strongest earthquake has a magnitude (not points!) No more than 9. This scale is logarithmic, that is, for example, an increase of one unit means an increase in energy of about 30 times, two units - 900 times.

Magnitude- a characteristic of the energy radiated from the source, and does not always correspond to what people feel on the surface. The greater the magnitude of the earthquake, the more powerful it is, the more destructive its consequences can be on the surface of the earth, that is, the higher the magnitude. However, there is no direct connection. Earthquakes of the same energy (or magnitude), whose sources are located at different depths, will be felt differently on the surface of the earth. So, a deep one can hardly be felt (1-2 points), and a shallow one, having the same magnitude, will cause catastrophic destruction (7-8 points), as, for example, happened in Tashkent in 1966. But then a tragic coincidence occurred: a shallow hearth was located almost under the center of the city, that is, the energy in the hearth was not so great, and the manifestations on the surface of the earth were catastrophic. Therefore, it is wrong to say that, for example, an earthquake measuring 7 on the Richter scale occurred in the ocean! In the ocean, there can’t be points at all, since events that take place on land are described by points: chandeliers sway, furniture moves, doors open, and cracks appear in the walls. That is, it is correct to say this: “An earthquake with a magnitude of 6.7 on the Richter scale occurred in such and such a country. An earthquake was felt at such and such points with a magnitude of 5, at such and such points with a magnitude of 4, and so on. on a 12-point scale." Or like this: "In such and such an area Pacific Ocean registered an earthquake with a magnitude of 7.4 on the Richter scale. The strength of the tremors on the coast was 1-2 points.

By the way, the information about an earthquake supposedly coming soon in the Crimea is not true. This was reported by the press service of the Main Directorate of the Ministry of Emergency Situations of Ukraine in the Autonomous Republic of Crimea. The seismic situation in the Crimea is within the normal range, that is, it does not exceed the permissible regulatory seismic impacts.

Reference

Richter scale

Magnitude/Earthquake

0 to 4.3 - mild
from 4.4 to 4.8 - moderate
from 4.9 to 6.2 - average
from 6.3 to 7.3 - strong
from 7.4 to 8.9 - catastrophic

More than 2,000 years ago, a device was created in China to warn people of an upcoming earthquake. This device had the shape of 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 shook the device and the balls fell out of their nests on 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 2,000 years for the infamous decision of an international conference in London in 1996 to appear that earthquake prediction is impossible. Does this mean that the efforts of thousands of scientists who devoted their lives to solving this problem of mankind and the billions of dollars spent on research were in vain? The fact that this decision was made by "skeptics", as they call scientists who have lost hope of finding a positive result in the study of a particular problem, out of desperation, 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 Emergencies Ministry received a warning from the Armenian Emergencies Ministry three months before the tragedy, when the city of Neftegorsk disappeared from the face of the Earth. At the beginning of the 20th century, changes in the ratio of longitudinal (VP) and transverse (VS) seismic waves were obtained for the first time in the development zone of the source strong earthquakes. And this attitude became the first harbinger of earthquakes. Scientists in many developed countries The world began to conduct research in order to create an earthquake prediction 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 issue of earthquake prediction remained unanswered. What is the reason for the failure? By catastrophic consequences that lead to a huge number casualties and destruction, earthquakes are the most dangerous natural disasters. The number of earthquake victims in the 20th century was 1.4 million (Osipov, 2001), of which about 1.0 million victims occurred in the last 30 years. For the first 12 years, the 21st century, the number of deaths from earthquakes is approaching 1.0 million (about 800,000): Indonesia (Sumatra, 2004) - about 300,000; Haiti, about 300,000; Japan (Fukushima) ... Every year there are: 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 go up. Scientists from all over the world have been and are engaged in the issue of earthquake prediction, and billions of dollars have been spent on these studies, but earthquakes continue to destroy cities, people, and countries. What is the reason for the helplessness of scientists all over the world? Politicians and the Ministry of Emergency Situations are not interested in these issues, but the Governments turn to them when a disaster occurs and people, cities and countries die. at the London conference in 1996. many experts have come to the conclusion that seismic forecasting is hopeless. As a result of the conference, it was published: “Seismic forecasting is hopeless? Complete pessimism about the possibility of a reliable earthquake prediction was expressed by some geophysicists at an international conference held in November 1996 in London. R. Geller (R. Geller; University of Tokyo) noted that, despite the efforts and funds expended by the international community of scientists, over the past decades, it has not been possible to detect a single trustworthy sign of an impending seismic event (some signals that are at the noise level or even below, undue importance has been given). Seismologist S.Crampin (S.Crampin; University of Edinburgh, Scotland) joined this opinion. Experts' skepticism intensified after several Greek seismologists said that they allegedly managed to predict earthquakes from previous variations. magnetic field Earth; in a strong criticism of their report, they pointed to completely vague information about the place and time of the upcoming shocks, about 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. It is almost impossible to predict exactly when a critical event will occur; according to seismologist I.Main (I.Main; University of Edinburgh), it is as difficult to predict an earthquake as it is to determine in advance which snowflake will cause an avalanche in the mountains. However, having attributed tremors to the category of critical phenomena, specialists can now make new amendments to building codes, taking into account scientific criteria seismic resistance of structures ( existing rules mostly based on bare empiricism). 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 (Tokyo University) and two employees of the University of Edinburgh, pronounced a verdict on more than a hundred years of work world scientists about the impossibility of pre-determining 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 adoption of the London decision, the author of these lines developed a physical model that allows theoretically calculating the parameters of future earthquakes on the planet: place (latitude and longitude coordinates), time (year, month and day) and strength (magnitude) for an unlimited time forward - a technique for short-term forecasting of earthquakes and other natural disasters (Publications: 1. Earthquake forecasting. 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 Sciences of Ecology and Life Safety, St. Petersburg, No. 7(19), 2000, 3. The regularity of the connection of seismic waves emitted by the source of earthquakes. "Bulletin" of the International Academy of Sciences 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, 2 000, p. 135. 5. Earthquakes and natural disasters shorth-term prediction. Sankt-Peterburg. 2000, p. 128.) and the parameters of the Sakhalin earthquake (May, 1995), after which the city of Neftegorsk disappeared from the face of the Earth, were calculated and transferred to the EMERCOM of Russia (three months before the tragedy) (publications: "Komsomolskaya Pravda", 06/06/1995 Moscow, Russia; "Shukan Shincho", 07/07/1995, Tokyo, Japan; BBC, 1995, London, Great Britain; Turkey, "Marmara" 1995; Iran, "Alik" 1995; USA ... more than 20 countries). Over the past 17 years, using this technique, the parameters (place, time and magnitude) of more than 40,000 future earthquakes and other natural disasters have been calculated, with an accuracy of 95%, including all catastrophes that have occurred during this time. Moreover, it is really not possible with the probabilistic research methods used by modern seismology. Therefore, until now, all the efforts of scientists in this direction of seismology fail. What is the difference between the studies currently being conducted and those that were applied in 1996? Nothing, only the quantity and, possibly, the quality of the equipment used has increased. Therefore, count on success in solving the problem of short-term earthquake forecasting " modern methods instrumental research" is not necessary. In this matter, the London Conference would have been more useful if, in its decision, it had been added; "modern methods of instrumental research". Short-term forecast of earthquakes and other natural disasters is possible and it exists. predict future natural disasters with absolute accuracy is possible, for an unlimited time ahead The method consists of two parts. 1. A theoretical calculation of the place, time and strength of future earthquakes is carried out ... 2. A month before the calculated time, the seismic stations of the given country conduct research on changes in the parameters of the specified region and refine the theoretical calculation. This will allow, 3-4 days before the earthquake, to accurately indicate the place, time and strength of the future earthquake. 3. The received accurate data of a future earthquake, tsunami ... are transferred to the Government, which will decide on the safety of people's lives.

Publication date 17.07.2011 20:32

In media reports, on the Internet, in the press, each person regularly encounters the fact that earthquake strength usually given in points. Everyone has long been accustomed to such characteristics. The associations are quite simple: 12 points is the most powerful, destructive earthquake, and 1 point is the weakest and most insignificant. But what earthquake consequences can be in each case? Which disaster is considered strong, and which - weak? What is this scale for measuring earthquakes? How does it differ from the equally popular "magnitude" characteristics?

In fact, the usual earthquake measurement technique is the international MSK-64 system based on the 1902 Mercalli-Cancani scale. This system is often confused with the 9-point Richter scale, which characterizes the strength of shocks, which is recorded by a seismograph. So, for example, the message in the media "earthquake with a magnitude of 6.0" means only that there was a push of the appropriate power. But the message "earthquake with a magnitude of 10" is a clear description of the destruction caused by tremors in a particular area.

Every level that can have earthquake force, has well-defined consequences. The site "Survival" brings to your attention detailed description each level, from 1 to 12 points. This knowledge will help you better navigate the flow of information that comes about in different parts the globe and correctly assess earthquake forecasts.

seismic scale

1 point- fluctuations are felt exclusively by devices. The person does not feel any hesitation.

2 points- fluctuations can be felt only by people who are in a calm, motionless state.

3 points- fluctuations are felt by some people who are at home.

4 points- fluctuations are felt by most people. Windows can rattle in buildings.

5 points- Vibrations can wake up a sleeping person. In rooms, it is not difficult to notice the swinging of hanging objects (for example, lamps or chandeliers).

6 points- some cosmetic damage is applied to the buildings, small cracks may occur in the plaster.

7 points- inevitable cracks in the plaster, its partial destruction. Cracks appear in the walls, and in some buildings there is a threat of partial collapses.

8 points- significant structural damage to buildings: large cracks in the walls, collapse of balconies, cornices and chimneys.