Innovative seismograph from the Japanese.
In early July, the Japanese Meteorological Agency JMA (Japan Meteorological Agency) began to lay a new fiber-optic cable under the Pacific Ocean. However, this cable is not intended for telecommunication needs: it is part of the most modern monitoring system that sends alarm signals when destructive earthquakes are recorded near the coast of Japan.
Underwater earthquakes pose a special danger because they generate tsunamis - a giant wave of immense power. In the past, Japan has repeatedly been subjected to the invasion of deadly waves. The most famous tsunami series was observed in December 2004 after the earthquake, the epicenter of which was not far from Indonesia. Then, according to some sources, the wave buried more than 225 thousand people under it.
A new fiber-optic cable is planned to be laid 220 kilometers off the southern coast of Japan, near the Shizuoka Prefecture - in an area where a large earthquake is predicted by seismologists for a long time with a high degree of probability. Nine large “cocoon” tips are attached to the cable, each of which is 2 meters long and 26 cm wide. Such attachments were specifically designed for the needs of this project by NEC engineers.
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The cable is located in a large round storage, which occupies several compartments in the center of the ship. Five nozzles contain earthquake sensors, three have tsunami sensors, and another one controls the signal relay, which is responsible for transmitting information from the farthest point of the cable to the shore. After arriving at the shore, the signals are sent further to the processing centers located in Tokyo and Osaka. These two cities are located a few hundred kilometers from each other, therefore, as it is supposed, even if one of them suffers from an earthquake, the other must continue to work.
The data collected by such devices will help to better determine the epicenter and scope of the earthquake, as well as to assess the likelihood of a tsunami.
Japan is located in one of the most seismically active zones in the world. Here several earthquakes are recorded every day that are strong enough to allow people to feel their impact without special devices. The country has created a nationwide earthquake warning system, using all the latest developments of scientists. As a rule, information about the epicenter and intensity of the earthquake is distributed by JMA and broadcast on television within two to three minutes after its registration. An integral part of the notification system is the publication of information about whether there is a danger of the formation of a tsunami.
Among the latest innovations should be noted the early warning system, which disseminates relevant information for a few seconds before the occurrence of strong shocks. The system controls the rapid movement of water, and the appearance of a weak primary wave allows the instruments to quickly identify the approximate location and intensity of the earthquake by sending out a warning about the possibility of approaching more destructive secondary waves.
Recently, a warning system about 13 seconds before the occurrence of strong aftershocks sent notifications to a million residents of the city of Sendai, located in northern Japan. The warning system is still not able to promptly notify everyone who is in close proximity to the epicenter, but at the end of October last year, the first such funds were already put into operation.
The new cable is laid by the Subaru vessel, which was specially built to perform such work and belongs to the largest Japanese telecommunications operator, NTT.
At the depth of the cable rests directly on the ocean floor, but closer to the shore it is necessary to dig a trench in order to protect the cable from various damage. The trench is excavated by a special earth moving installation, which is fixed at the stern and lowered into the water as such a need arises.
Underwater earthquakes pose a special danger because they generate tsunamis - a giant wave of immense power. In the past, Japan has repeatedly been subjected to the invasion of deadly waves. The most famous tsunami series was observed in December 2004 after the earthquake, the epicenter of which was not far from Indonesia. Then, according to some sources, the wave buried more than 225 thousand people under it.
A new fiber-optic cable is planned to be laid 220 kilometers off the southern coast of Japan, near the Shizuoka Prefecture - in an area where a large earthquake is predicted by seismologists for a long time with a high degree of probability. Nine large “cocoon” tips are attached to the cable, each of which is 2 meters long and 26 cm wide. Such attachments were specifically designed for the needs of this project by NEC engineers.
')
The cable is located in a large round storage, which occupies several compartments in the center of the ship. Five nozzles contain earthquake sensors, three have tsunami sensors, and another one controls the signal relay, which is responsible for transmitting information from the farthest point of the cable to the shore. After arriving at the shore, the signals are sent further to the processing centers located in Tokyo and Osaka. These two cities are located a few hundred kilometers from each other, therefore, as it is supposed, even if one of them suffers from an earthquake, the other must continue to work.
The data collected by such devices will help to better determine the epicenter and scope of the earthquake, as well as to assess the likelihood of a tsunami.
Japan is located in one of the most seismically active zones in the world. Here several earthquakes are recorded every day that are strong enough to allow people to feel their impact without special devices. The country has created a nationwide earthquake warning system, using all the latest developments of scientists. As a rule, information about the epicenter and intensity of the earthquake is distributed by JMA and broadcast on television within two to three minutes after its registration. An integral part of the notification system is the publication of information about whether there is a danger of the formation of a tsunami.
Among the latest innovations should be noted the early warning system, which disseminates relevant information for a few seconds before the occurrence of strong shocks. The system controls the rapid movement of water, and the appearance of a weak primary wave allows the instruments to quickly identify the approximate location and intensity of the earthquake by sending out a warning about the possibility of approaching more destructive secondary waves.
Recently, a warning system about 13 seconds before the occurrence of strong aftershocks sent notifications to a million residents of the city of Sendai, located in northern Japan. The warning system is still not able to promptly notify everyone who is in close proximity to the epicenter, but at the end of October last year, the first such funds were already put into operation.
The new cable is laid by the Subaru vessel, which was specially built to perform such work and belongs to the largest Japanese telecommunications operator, NTT.
At the depth of the cable rests directly on the ocean floor, but closer to the shore it is necessary to dig a trench in order to protect the cable from various damage. The trench is excavated by a special earth moving installation, which is fixed at the stern and lowered into the water as such a need arises.
Source: https://habr.com/ru/post/37130/
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