Kiyoo Mogi
Encyclopedia
Dr is a prominent seismologist
Seismology
Seismology is the scientific study of earthquakes and the propagation of elastic waves through the Earth or through other planet-like bodies. The field also includes studies of earthquake effects, such as tsunamis as well as diverse seismic sources such as volcanic, tectonic, oceanic,...

. He is regarded as Japan's foremost authority on earthquake prediction
Earthquake prediction
An earthquake prediction is a prediction that an earthquake of a specific magnitude will occur in a particular place at a particular time . Despite considerable research efforts by seismologists, scientifically reproducible predictions cannot yet be made to a specific day or month...

 and is a former chair of the Japanese Coordinating Committee for Earthquake Prediction
Coordinating Committee for Earthquake Prediction
The Coordinating Committee for Earthquake Prediction in Japan was founded in April 1969, as part of the Geodesy Council's Second Earthquake Prediction Plan, in order to carry out a comprehensive evaluation of earthquake data in Japan. The committee consists of 30 members and meets four times each...

 (CCEP). Mogi is also a former Director of the University of Tokyo's Earthquake Research Institute
Earthquake Research Institute, University of Tokyo
Earthquake Research Institute, University of Tokyo is the institute in affiliation with University of Tokyo. It was founded in 1925. Many fellows research on various topics about Seismology and volcanology...

, was a professor at Nihon University
Nihon University
Nihon University is the largest university in Japan. Akiyoshi Yamada, the minister of justice, founded Nihon Law School in October 1889....

 and is professor emeritus at Tokyo University. Due to the seismic activity in Japan, Mogi has also taken an interest in safety of nuclear power in Japan
Nuclear power in Japan
Nuclear energy was a national strategic priority in Japan, but there has been concern about the ability of Japan's nuclear plants to withstand seismic activity...

.

In 1969 Mogi predicted that there was a possibility of a shallow magnitude
Moment magnitude scale
The moment magnitude scale is used by seismologists to measure the size of earthquakes in terms of the energy released. The magnitude is based on the seismic moment of the earthquake, which is equal to the rigidity of the Earth multiplied by the average amount of slip on the fault and the size of...

 8.0 earthquake
Earthquake
An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time...

 in the Tōkai region
Tokai region
The is a sub-region of the Chūbu region in Japan that runs along the Pacific Ocean. The name means "East sea" and comes from the Tōkaidō, one of the Edo Five Routes...

 of Japan, an area that has experienced a number of previous large earthquakes
Tokai earthquakes
The Tōkai earthquakes are major earthquakes that have occurred regularly with an interval of 100 to 150 years in the Tōkai region of Japan. The Tokai segment has been struck by earthquakes in 1498, 1605, 1707 and 1854...

. Following the passing of the Large-Scale Earthquake Countermeasure Act
Large-Scale Earthquake Countermeasure Act
The Large-Scale Earthquake Countermeasures Act is a Japanese law that was passed in June 1978 and came into effect in December 1978.The Act put into place an integrated set of measures and created several bodies at national, prefecture and local levels...

, in 1978 Mogi was appointed to the newly created Earthquake Assessment Committee (EAC) for the expected Tokai earthquake, charged with warning the government if the quake was imminent. He went on to chair the ECA from 1991 until he resigned the post in 1996 after failing to persuade the government of the need to take uncertainty into account when issuing warnings.

Nuclear power

Following damage at the Kashiwazaki-Kariwa Nuclear Power Plant
Kashiwazaki-Kariwa Nuclear Power Plant
The is a large, modern nuclear power plant on a 4.2-square-kilometer site including land in the towns of Kashiwazaki and Kariwa in Niigata Prefecture, Japan on the coast of the Sea of Japan, from where it gets cooling water...

 due to the 2007 Chūetsu offshore earthquake
2007 Chuetsu offshore earthquake
The Chūetsu Offshore Earthquake was a powerful magnitude 6.6 earthquake that occurred 10:13 a.m. local time on July 16, 2007, in the northwest Niigata region of Japan. The earthquake shook Niigata and neighbouring prefectures...

, Mogi called for the immediate closure of the Hamaoka Nuclear Power Plant
Hamaoka Nuclear Power Plant
The is a nuclear power plant located in Omaezaki city, Shizuoka Prefecture, on Japan's east coast, 200 km south-west of Tokyo. It is managed by the Chubu Electric Power Company. There are five units contained at a single site with a net area of 1.6 km2 . A sixth unit began construction...

, which was built close to the centre of the expected Tōkai earthquake despite his 1969 prediction. Previously, in 2004, he had stated that the issue 'is a critical problem which can bring a catastrophe to Japan through a man-made disaster'.

Mogi doughnut hypothesis

In 1969 Mogi proposed a hypothesis
Hypothesis
A hypothesis is a proposed explanation for a phenomenon. The term derives from the Greek, ὑποτιθέναι – hypotithenai meaning "to put under" or "to suppose". For a hypothesis to be put forward as a scientific hypothesis, the scientific method requires that one can test it...

 for earthquake prediction, now known as the 'Mogi doughnut hypothesis', that major earthquakes tend to occur in an unusually seismically calm area surrounded by a ring of unusually high seismic activity. The Mogi doughnut is one of several pattern hypotheses that have been proposed.

Mogi model

In 1958 Mogi was responsible for a major advance in understanding the dynamics of volcano
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...

s. After studying data from several sources, he concluded that a mathematical solution developed by Yamakawa in 1955 could be used in the modelling of the deformation of a volcano caused by pressure changes in its magma chamber
Magma chamber
A magma chamber is a large underground pool of molten rock found beneath the surface of the Earth. The molten rock in such a chamber is under great pressure, and given enough time, that pressure can gradually fracture the rock around it creating outlets for the magma...

. The 'Mogi model' (also known as the 'Mogi-Yamakawa model') subsequently became the first commonly used quantitative method in volcanology
Volcanology
Volcanology is the study of volcanoes, lava, magma, and related geological, geophysical and geochemical phenomena. The term volcanology is derived from the Latin word vulcan. Vulcan was the ancient Roman god of fire....

, and is still widely used today.

See also

  • Hamaoka Nuclear Power Plant
    Hamaoka Nuclear Power Plant
    The is a nuclear power plant located in Omaezaki city, Shizuoka Prefecture, on Japan's east coast, 200 km south-west of Tokyo. It is managed by the Chubu Electric Power Company. There are five units contained at a single site with a net area of 1.6 km2 . A sixth unit began construction...

  • Fukushima I nuclear accidents
  • Katsuhiko Ishibashi
    Katsuhiko Ishibashi
    is a professor in the Research Center for Urban Safety and Security in the Graduate School of Science at Kobe University, Japan and a seismologist who has written extensively in the areas of seismicity and seismotectonics in and around the Japanese Islands...

  • Nuclear power in Japan
    Nuclear power in Japan
    Nuclear energy was a national strategic priority in Japan, but there has been concern about the ability of Japan's nuclear plants to withstand seismic activity...

  • Geology of Japan
    Geology of Japan
    The islands of Japan are primarily the result of several large oceanic movements occurring over hundreds of millions of years from the mid-Silurian to the Pleistocene as a result of the subduction of the Philippine Sea Plate beneath the continental Amurian Plate and Okinawa Plate to the south, and...

  • Pacific Ring of Fire
    Pacific Ring of Fire
    The Pacific Ring of Fire is an area where large numbers of earthquakes and volcanic eruptions occur in the basin of the Pacific Ocean. In a horseshoe shape, it is associated with a nearly continuous series of oceanic trenches, volcanic arcs, and volcanic belts and/or plate movements...

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK