Seismic data around the world. Seismic monitoring or map of earthquakes online in the world
METHODOLOGICAL
INSTRUCTIONS
for practical classes in the discipline:
"Construction Engineering: Geology"
For students in the field of study
Construction"
Full-time and part-time forms of study
Stavropol
Methodological instructions for practical classes are compiled in accordance with the program in the discipline “Construction Engineering: Geology” for bachelors in the field of preparation 270800.62 “Construction” of all forms of study.
The guidelines can be used for students’ independent work.
Compiled by: Kuznetsov R.S.
Baranda E.G.
Practical lesson No. 1……………………………………………………………4
Practical lesson No. 2……………………………………………………………17
Practical lesson No. 3……………………………………………………………29
Practical lesson No. 4……………………………………………………………32
Practical lesson No. 5……………………………………………….…45
Practical lesson No. 6……………………………………………….…53
References…………………………………………………………………….………57
PRACTICAL WORK No. 1
HAZARDOUS GEOLOGICAL PHENOMENA: EARTHQUAKES
1. Theoretical part
Earthquakes- These are tremors and vibrations of the earth's surface, arising mainly as a result of sudden displacements and ruptures in the earth's crust or upper mantle and transmitted over long distances.
Vibrations of the earth's surface during earthquakes are of a wave nature. Ground vibrations excite vibrations of buildings and structures, causing inertial forces in them. If their strength (seismic resistance) is insufficient, they are destroyed, utility power networks are disabled, and human casualties are possible. Seismic hazard during earthquakes is determined not only by ground vibrations, but also by possible secondary factors, which include avalanches, landslides, landslides, subsidence (subsidence) and distortions of the earth's surface, soil destruction, floods due to the destruction and breakthrough of dams and protective dams, as well as fires. If an earthquake occurs underwater, it creates huge tsunami waves that cause destruction on land.
The earth consists of several shells-geospheres. The mantle and the earth's crust form the lithosphere. The temperature in the mantle is considered to be 2000 - 2500 0 C, and the pressure is up to 130 GN/m 2. Processes occur in the mantle that cause earthquakes.
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The most common cause of earthquakes is the appearance of excessive internal stresses and rock destruction. The potential energy accumulated during elastic deformation of the rock, upon destruction (fault), is converted into the kinetic energy of a seismic wave in the soil (see figure). An earthquake of this kind is called tectonic. Along with tectonic processes, earthquakes can also occur for other reasons. One of these reasons is volcanoes. The eruption of lava from the crater is accompanied by the release of energy and gives rise to volcanic earthquakes. Compared to tectonic phenomena, seismic tremors caused by volcanic activity are a less dangerous natural phenomenon, since most of the energy is discharged into the atmosphere.
Another category is formed landslide earthquakes that occur as a result of the collapse of mine roofs or underground voids and cause waves in the ground. These earthquakes are classified as weak.
Earthquake source- the volume within the Earth where maximum energy is released.
A series of tremors typically includes: foreshocks, main push And aftershocks. The most dangerous earthquakes are those in which foreshocks do not occur, and the first shock is the maximum in energy - the main shock.
Hearth center - hypocenter, and the projection of the hypocenter onto the Earth's surface is called epicenter. Depending on the depth (H) of the hypocenter, earthquakes are divided into normal (at a depth of up to 70 km), intermediate (from 70 to 300 km) and deep-focus (more than 300 km).
The distance from the hypocenter to a certain point on the earth's surface is hypocentral distance:
where R is the epicentral distance (km).
Shift of the soil surface within a radius R< Н считают эпицентральным. В этой зоне преобладают колебания грунта вертикального направления. По мере удаления от эпицентра усиливаются горизонтальные колебания, которые представляют наибольшую опасность для зданий.
Earthquakes, in terms of their destructive consequences and the number of human casualties, occupy one of the first places among natural disasters.
Statistics of the largest earthquakes in the twentieth century
Every year about 10 thousand people die in earthquakes.
1997 – 2907 people died.
1998 – 8928 people died.
1999 – more than 22 thousand people died. There were 20 significant earthquakes (above 7 on the Richter scale).
In August 1999, 17 thousand people died in Turkey. The earthquake measured 7.4 on the Richter scale. On November 12 there is another one (7.1 Richter points).
1999 - an earthquake in Taiwan (7.6 points) claimed only 2.4 thousand lives, because The earthquake resistance of buildings was higher than in Turkey.
The most terrible earthquakes in terms of the number of deaths were in 1201 in Egypt, when 1 million 100 thousand people died, and in 1556 in China - 830 thousand people. died.
On Earth, on average every year:
One strong (magnitude 8 or higher) earthquake;
18 significant (7-7.9 points);
Several million (about 50 times a day) are minor, most of which are recorded only by seismic-sensitive instruments.
In 1943, a record number of large (more than 7.0 magnitude) earthquakes was recorded - 41.
Strength (energy) of the earthquake (E),usually, measured in magnitudes(from lat. magnitudo- size) (M), Richter scale(1935). The Richter scale is essentially the maximum amplitude of soil displacement measured from a seismogram in micrometers (1µm = 0.001mm).
Richter magnitude is the decimal logarithm of this amplitude reduced to the standard distance.
Earthquake Energy E related to magnitude M ratio:
In an earthquake for which M = 5, the energy is E » 10 12 J. On the seismic Richter scale, the strongest earthquake corresponds to a magnitude of 9. Magnitude allows you to compare vibration sources by their energy. Since the magnitude scale is logarithmic, an increase in magnitude by one means a tenfold increase in the amplitude in the wave (or ground displacement). The amplitude of seismic waves from an earthquake with a magnitude of 6.0 is ten times greater than that of an earthquake with a magnitude of 5.0, and 100 times greater than that of a magnitude 4.0.
Zero magnitude is a very weak earthquake with an amplitude of 1 micron (zero is the logarithm of 1), which is recorded by a seismograph at a distance of 100 km.
The magnitude scale does not have an upper limit, since it is a calculated scale. For this reason, the Richter scale is also called an “open scale.” The strongest earthquake that was recorded had a magnitude of 8.9 (off the coast of Japan in 1933 and off the coast of Ecuador in 1906).
The occurrence of an earthquake in certain areas is called seismicity. Seismicity is quantitatively characterized as magnitude, so intensity.
Earthquake intensity- a value that evaluates the strength of an earthquake based on the damage caused (degree of damage). Its definition is subjective, based on damage and destruction. Several scales are used to measure the intensity of an earthquake.
In the Russian Federation, as well as throughout Europe, 12 are used you point modified international seismic scale (Arabic numerals from 1 to 12) MMSK-86, which received its name from the seismologists who proposed it (in 1964) (S.V. Medvedev - USSR, Sponheuer - GDR, Karnik - Czechoslovakia). Initially, this scale was compiled in relation to buildings and structures that do not have earthquake-resistant reinforced structures. In the range from 6 to 9 points on the IPE scale (Institute of Earth Physics), recommended by the Bureau of the Interdepartmental Council on Seismology and Seismic Construction of the Russian Academy of Sciences, the intensity of an earthquake is determined by the parameters of vibrations on the earth's surface (see table 1.).
Today it is no longer a secret to anyone that on all continents of our planet there is a significant increase in cataclysms and natural disasters that are associated with cosmic cyclical processes and, as a consequence, global climate change. The increase in activity and frequency of natural disasters on a planetary scale is due to seismic activity. Scientists around the world are concerned about the constantly changing data on the increase in the number of earthquakes. Not only their number increases, but also the intensity, location, and nature of destructive actions.
Thus, an area of special attention for the scientific direction of climate geoengineering and the entire world community today are two points on different hemispheres of the globe - the Yellowstone caldera in the USA and the Aira caldera in Japan. These are two huge underground volcanoes located at the junction of lithospheric plates. According to scientists, the activation of one of them can lead to the subsequent activation of the other, and this is not only a large-scale eruption, but also earthquakes, tsunamis and other consequences. The scale of such a global catastrophe is difficult to assess.
This and other important issues of early warning of people about impending cataclysms were openly stated in 2014 by the global community of ALLATRA SCIENCE scientists in the report “On the problems and consequences of global climate change on Earth. Effective ways to solve these problems."
Earthquake.
According to official terminology, an earthquake is a vibration of the earth's surface or underground points that are a reflection of the internal geological changes of the planet. The basis for this effect is the displacement of tectonic plates, which lead to ruptures in the earth’s crust and mantle. As a result, oscillatory movements, depending on the intensity of the process, can spread over long distances, bringing with them not only a destructive effect on social infrastructure, but also a threat to people’s lives.
This issue is dealt with by a special science – seismology. Several areas are being actively studied, including: deepening the knowledge of what seismic activity is in essence and what it is connected with, possible forecasting of these natural disasters, for timely warning and evacuation of people. Like any other science, seismology can actively develop only in a mutually beneficial symbiosis with other sciences (physics, history, biology, geophysics, etc.), since the fundamental basis for all knowledge on our planet is, of course, common.
Seismic activity online and in the world.
Seismic monitoring is developing in most countries, regardless of the territory, frequency and threat of earthquakes. In addition, a seismic monitor is one of the fundamental factors in the development and preservation of the integrity of energy industry facilities. Almost every person on the planet today is an active consumer of electricity. Therefore, power plants are located in all countries and on all continents, including areas of high seismic hazard. The action of such a destructive force of nature is fraught not only with an energy disaster, but also with global environmental problems.
In order to control seismic processes (earthquakes), study them and warn the public in advance about their occurrence, seismic stations are built in designated areas. All necessary characteristics of tremors are studied - magnitude, location and depth of the source.
Earthquakes online.
Thanks to Internet technologies, data is also available to all people today: “earthquakes online.” This is the so-called earthquake map, which provides information about tremors around the world around the clock.
Active participants of the ALLATRA International Public Movement have developed the most complete map of seismic activity, which displays objective data from world information portals and seismic monitoring stations. Informing the public and awareness of the processes occurring on the planet, their causes and consequences is the main goal of this project.
Today, everyone can observe a significant increase in abnormal weather changes, natural disasters, and cataclysms. The active participation of all people, unification, mutual assistance and friendship, the prevalence of true moral and spiritual values in society is the key to the survival of civilization in the future.
On April 25, 2015, one of the most destructive earthquakes on the planet occurred in Nepal, which claimed the lives of more than 3,000 people and turned many buildings and historical monuments into ruins. According to experts, Nepalese residents may experience new aftershocks in the coming week. In our review of the 10 most destructive earthquakes that occurred on Earth over the last century.
1. Valdivia, Chile
This earthquake, which occurred in 1960, was the strongest recorded in history, reaching a maximum of 9.5 on the Richter scale. This can be compared to the simultaneous explosion of 1000 atomic bombs. The earthquake was felt not only in Valdivia, but also in the Hawaiian Islands - 700 km away. During the disaster, which destroyed Valvidia, Concepción and Puerto Montt, 6,000 people died. Material damage amounted to more than $1 billion.
2. Sumatra, Indonesia
On December 26, 2004, a magnitude 9.3 earthquake occurred at the bottom of the Indian Ocean, which caused a huge tsunami. It was the second most seismically active earthquake in the world, and the longest duration of tremors recorded. Even the Maldives and Thailand suffered from its consequences, as more than 5 tsunamis hit the entire coast of the Indian Sea. 225,000 people died, and in just the first 10 minutes of the disaster, the damage from it amounted to more than $7 billion.
3. Tanshan, China
On July 28, 1976, an earthquake occurred in the Chinese province of Hebei, leveling the city of Tangshan. 255,000 people died, although the Chinese government initially claimed 655,000 dead. The magnitude 8.2 earthquake lasted only 10 seconds but caused massive destruction in the area. Hebei is a region with a very low risk of earthquakes, so the buildings in Tangshan were not earthquake resistant. Total damage was 10 billion yuan, or $1.3 billion.
4. Tashkent, Uzbekistan, USSR
In the early morning of April 26, 1966, an earthquake with a magnitude of 8 occurred in Tashkent. The zone of maximum destruction was 10 square meters. kilometers. 8 people died, 78 thousand families were left homeless. More than 2 million square meters of buildings were destroyed.
5. Port-au-Prince, Haiti
The strength of the earthquake in Haiti, which occurred on January 12, 2010, was 7.0 on the Richter scale. The epicenter of the tremors was located near Leogane, 25 km west of the capital of Haiti, Port-au-Prince. At least 52 tremors were recorded, which were felt even after 12 days. The earthquake resulted in 316,000 deaths, 300,000 people were injured, and more than a million people were left homeless. 250,000 homes and 30,000 commercial buildings were also destroyed.
6. Tohoku, Japan
On March 11, 2011, the east coast of Japan was hit by a magnitude 9.03 earthquake, which was the strongest in the country's history. The earthquake, considered one of the world's five largest, resulted in 15,878 deaths, 6,126 injuries and 2,173 missing in 20 prefectures. It also destroyed 129,225 buildings, and the tsunami caused by the earthquake led to severe infrastructure damage and fires in many areas. The Fukushima nuclear power plant was severely damaged, leading to radioactive contamination. As a result, Japan faced its biggest crisis since World War II.
7. Ashgabat, USSR
This earthquake of magnitude 7.3 occurred on October 6, 1948 near Ashgabat. Due to censorship, it was not reported in the media, so there was no information about casualties or destruction. The number of victims is estimated at 110,000 people, and 98% of all buildings in Ashgabat were destroyed.
8. Sichuan, China
On May 8, 2008, a magnitude 8.0 earthquake occurred in the Chinese province of Sichuan. It was so strong that it was felt in neighboring countries, as well as in distant Beijing and Shanghai, where buildings swayed from the tremors. According to official data, the death toll was 69,197 people. 374,176 people were injured and 18,222 are considered missing. The Chinese government has allocated 1 trillion yuan or $146.5 billion to rebuild areas that were damaged by the earthquake.
9. Kashmir, Pakistan
On October 8, 2005, the disputed region of Pakistan and India, Kashmir, was hit by an earthquake measuring 7.6 on the Richter scale. The disaster killed 85,000 people, injured more than 69,000, and left 4 million Kashmiris homeless.
10. Izmit, Türkiye
A magnitude 7.9 earthquake struck northern Turkey on August 17, 1990. Although it lasted only 3.7 seconds, the city of Izmit was practically reduced to ruins. Officially there were 17,127 casualties and 43,959 wounded, although other sources put the actual death toll at 45,000. The earthquake destroyed 120,000 poorly designed houses and severely damaged 50,000 other buildings. More than 300,000 people were left homeless.
Fortunately, despite the time and the elements, there are places on the planet today that are definitely worth visiting.
Hello everyone! Evgenia Klimkovich is in touch.
How much a person can do! Today he controls iron machines, lifting them into the air thousands of kilometers, creates robotic assistants for the home, and leaves his traces in outer space. But no power of the most intelligent creature on Earth can cope with nature. She dictates her own rules of life, periodically reminding who is the boss on the planet.
Today I will tell you what the strongest earthquakes in the world have happened over the last 100 years in human history, what consequences they brought, and what victims the seismic regions had to face.
Lesson plan:
Chinese earthquake in Haiyuan
One of the deadliest disasters of the 20th century occurred on December 16, 1920 and covered an area of 3.8 square kilometers. The strength of the waves, recorded by seismographs at 7.8 on the Richter scale, caused waves even off the coast of Norway.
After the tremors, landslides followed and cracks appeared in the earth's surface. Entire Chinese settlements floated into the fractured depths of the earth's crust, and almost all residential buildings in the large cities of Lanzhou, Taiyuan and Xi'an were destroyed.
59 percent of the population of the epicenter of the earthquake, the city of Haiyuan, died from destructive tremors or froze from the cold and found themselves homeless. The disaster killed more than 230,000 people.
Japanese Kanto disaster
Occurred on September 1, 1923 and received a rating of 8.3 points. The earthquake was named after the province where the main impact occurred. It is also called Tokyo or Yokohamxima because the disaster almost completely destroyed the cities of Tokyo and Yokohama.
The disaster was the most destructive in Japanese history. Over two days, 356 tremors occurred, the epicenter of which was located at sea depth. Coastal villages were destroyed by a twelve-meter tsunami. The fires that started spread over a large area with wind currents. The earthquake damaged buildings over an area of 56,000 square kilometers.
The estimated economic damage from the disaster was estimated at the country's two-year budget. There was even a question about moving the capital from the destroyed Tokyo.
Officially, 175,000 deaths were reported, but half a million residents were listed as missing. The total number of victims of the Japanese earthquake is estimated at 4 million, including a million people left homeless.
Earthquake in Turkmenistan
It is considered one of the most severe disasters of the 20th century, since the magnitude of the tremors was recorded at 9-10 points.
It began in Ashgabat on the night of October 6, 1948 and in a short period completely wiped out the city where 130,000 people lived, destroying 98% of the buildings. This day today in Turkmenistan has been declared a day of obedience. Tremors from the epicenter, located at a depth of 12 kilometers, were heard for another four days.
The number of victims was about 160,000 people.
Disaster in Chile
An earthquake with a magnitude of 9.5-10 tremors occurred on May 22, 1960, causing a tsunami with waves more than 10 meters high, which covered not only the Chilean coast itself, but also nearby Hawaii, the Philippines and the coast of Japan, moving at a speed of 700 kilometers per hour. hour, reaching California, located 17,000 kilometers from Chile.
6,000 people died, and about 100,000 residents were left homeless.
Tangshan earthquake
A natural disaster of eight on the Richter scale occurred on the night of July 28, 1976. It is considered the largest natural disaster of the 20th century. The first shock destroyed 90% of the city of a million people - 5.5 million houses, and the subsequent one 15 hours later buried under the rubble those who cleared the rubble.
The underground impacts continued until August 1, and in total there were about 130 of them with an average magnitude of about 4.5. The earthquake was felt 800 kilometers from its epicenter.
The Tangshan disaster, which unofficially claimed about 655,000 people, is considered the second-largest in human history after the Shaanxi disaster of 1556, which killed 800,000 people.
The Chinese disaster formed the plot of the film Earthquake.
Spitak disaster
On December 7, 1988, in half a minute, an earthquake almost completely destroyed the north of the Republic of Armenia, where more than a million people lived. The epicenter of the disaster was the city of Spitak, where the tremors reached 9-10 points, they were enough for the city to disappear. About 40% of Armenia's industry was put out of action, the city of Leninakan was severely damaged, and more than 300 settlements were partially destroyed.
Up to 150,000 residents became victims of the earthquake, and more than half a million were left without their homes.
In order to avoid a nuclear disaster, the work of the Armenian nuclear power plant was suspended.
At the end of the article you will find a video about this tragedy.
Russia, Sakhalin island
The earthquake, whose power at the epicenter reached 8 points, began on May 28, 1995. The village of Neftegorsk suffered the most.
The village was wiped off the face of the Earth in 17 seconds, killing 2,040 residents.
Echoes of the earthquake were heard in the north of Sakhalin in the city of Okha. Today, instead of the former Neftegorsk, a chapel and memorial are being built. Only slabs with carved numbers remind us of the houses demolished by the natural disaster.
Andaman earthquake
A widespread disaster that struck countries in the Indian Ocean on December 26, 2004. It was caused by an underwater earthquake off the coast of Indonesian Sumatra and was estimated at 9.1 points.
The worst disaster of the 21st century in the last 40 years brought a tsunami to the shores, which in 15 minutes washed away everything that was built on the island in its northern part. The earth's crust shifted 1,200 kilometers, giving the waves a speed of 720 kilometers per hour. Two hours after the first shock, waves covered the shores of Thailand and reached the coasts of India and Sri Lanka.
In eight hours, the tsunami traveled around the entire Indian Basin.
Experts have calculated the damage from the earthquake at $10.7 billion. About 230,000 people are listed as dead.
Earthquake on the island of Haiti
More than half of the residents of the capital Port-au-Prince were left homeless as a result of the disaster that occurred on January 12, 2010.
Until now, no one can accurately say the number of victims of the natural disaster; it is in the range of 160,000 - 220,000 people. The 7.1 magnitude earthquake deprived more than three million people of their property.
In terms of material damage, the disaster is the most destructive in the history of the state; experts estimate the loss at 5.6 billion euros. A charity telethon was organized to help the Haitians, in which many Hollywood stars took part.
Japan
Disaster on the island of Honshu. The source of the earthquake was located at a depth of 24 kilometers in the waters of the Pacific Ocean. The magnitude 9 tremor on March 11, 2011 caused a tsunami with ten-meter waves, flooding 327 square kilometers of area, most of it in the Miyagi area.
The natural disaster caused a nuclear disaster at the Fukushima nuclear power plant, leaving the surrounding areas uninhabitable.
The earthquake killed 15,890 people. The country's government estimated the economic damage from the disaster at $200 billion.
These are the sad natural disasters that have occurred in different parts of the world over the past 100 years, bringing pain and loss to families. These are just some of them that amazed the world with their scale, because nature makes itself felt by causing tremors hundreds of thousands of times a year. By the way, we considered in detail the question of why earthquakes occur.
I wish you success!
Evgenia Klimkovich.
The National Meteorological Administration of Japan has released statistics on earthquakes in the country recorded in 2016. The report included those that reached the first or higher strength level, in accordance with the Japanese 7-point seismic scale.
The Japan Meteorological Agency scale is used to rate the intensity of a seismic event. The scale is considered a 7-point scale, but actually contains 10 levels (from 0 to 4, 5 “weak”, 5 “strong”, 6 “weak”, 6 “strong” and 7).
The zero level includes tremors, which are detected only by special instruments, but are not felt by people.
The seventh level includes the most powerful earthquakes that people feel,at which maybe ohgeneral destruction of buildings and structures, Ain case of an underwater earthquake- tsunami.
According to the published report of the National Meteorological Administration of Japan, compiled as of December 29, for 2016 in Japan the number of tremors recorded with a strength higher than 1 point reached 6566, which is 3.5 times more than those registered in 2015, which amounted to 1842.
Let us recall that the number of tremors in Japan in 2011 was 7 times higher than normal. In the area of the Japanese archipelago, 9,723 tremors above magnitude 1 were recorded. Moreover, the bulk of them, approximately 7 thousand, were aftershocks after a powerful earthquake of magnitude 9.0 that shook northeastern Japan on March 11, 2011. Every year the number of earthquakes has steadily decreased and in 2015 it amounted to 1842, but in 2016 the number of earthquakes increased again.
In 2016, the country experienced several strong earthquakes with a magnitude greater than 5:
April 14-17, 2016 strong tremors of magnitude 6.5 and 7.3 were recorded at intervals of several days on the island of Kyushu.
December 30, 2016-the most recent earthquake, which was not included in the report, was of magnitude 5.5. The epicenter of the earthquake was located 37 km southeast of the village of Namie and 60 km northeast of the city of Iwaki located in Fukushima Prefecture.
The Japanese islands are part of the Pacific volcanic Ring of Fire system and are located at the junctions of tectonic plates. Mountains, including volcanoes, occupy 61% of the territory. About 7% of all volcanoes on the planet are concentrated on the Japanese archipelago, including the supervolcano - the giant volcanic caldera Aira, which today, due to the activity of its volcanoes, poses a serious danger.
You can learn more about the history and causes of earthquakes in the article
Seismologists warn that increased seismic activity will continue off the coast of Japan in the coming years and urge the population to be prepared for earthquakes and tsunamis at any time, as powerful tremors can happen anywhere in Japan.
