Dr. Aikitu Tanakadate

World-Renowned Geophysicist and Seismologist


"There are, in fact, two satellites orbiting the Earth. One we call the Moon, and the other is the eminent Dr.Tanakadate. Once a year we recall on Earth his international achievements."
Dr. Guillaume
Chief of the International Bureau of Weights and Measures


Profile of Dr. Aikitu Tanakadate's Early Life

1856 - Sept.18, born Ninohe City, Iwate Prefecture.
1864 - Commences studies in Chinese and Japanese literature
1868 - Martial Arts training
1873 - Enters Keiogijuku University to study English
1879 - Enters Tokyo University majoring in Physics (under tutelage of the American, Thomas C. Mendenhall)
Undertakes gravimetric measurements around Tokyo and Mt. Fuji Studies mechanical engineering under the Englishman, Ewing Both teachers influence him greatly
1882 - Graduates from Tokyo University, begins Assistant Professorship (his students gain prominence in Physics and Science in general)
1888 - Studies electricity and magnetism under Lord Kelvin at Glasgow University (United Kingdom)
(following Kelvin's death, Tanakadate never failed to visit his mentor's grave whenever he visited London)
1889 - Transfers to Berlin University, Germany
1890 - Returns to Japan

Throughout his life he also maintained an active interest in the movement to replace the traditional Japanese writing system with roman letters - having devised his own system.

Earthquake Investigation and Research

In 1891, a large earthquake struck the Nagoya district killing more than 7000 people. Following a request from Tokyo University, Dr. Tanakadate completed a study of the affected area. While feeling great sympathy for the victims of the disaster, he suggested that they remain constantly on alert should another earthquake strike. The government then formed a committee charged with effecting measures to counter future disasters.
Dr. Tanakadate went on to found the Institute of Seismology at Tokyo University, to which he devoted much of his time. in 1898, he attended the International Conference on Seismology in Strasbourg, as the representative of Japan. The conference opened with Dr. Robert Darwin (1809-1882) of England, Dr. Fernand Richthofen (1883-1905) of Germany and Dr. Tanakadate presiding as joint-chairmen.

Observatory of Magnetism, Gravitation and Latitude

Dr. Tanakadate became a member of the World Earth-Science Academic Society. He was also the first person to join the international Observatory of Magnetism, Gravitation and Latitude voluntarily and attended the Conference of Geophysicists, held in Stuttgart in 1898.
He attended a total of eight geophysics-related conferences and became familiar with geophysicists from all over the world.
Dr. Tanakadate was instrumental in the establishment of want is now the Mizusawa Astro-Geodynamics Observatory. He also had an influence on Dr. Hisashi Kimura (1870-1943) who followed in his footsteps. Dr. Kimura became the first director of the Mizusawa observatory and is renowned for discovering the Z-term (or Kimura-term) of latitude variation.

Organization of the Metric System of Weights and Measures

France was the first nation to take the initiative in establishing the Metric System and an international treaty was soon concluded among 18 countries.

Dr. Tanakadate was appointed to the standing committee of the organization attending the 1906 Paris conference on behalf of Asian countries. He attended a total of nine conferences and observed developments. He of measurement. The Diet was called into session and a reform bill presented. The bill was adopted during the sessions establishing the Metrics System in Japan.

Tanakadate and the Development of Aviation of Japan

At the 1907 Conference of the Metric System of Weights and Measures, an aeroplane was demonstrated by the French government. Dr. Tanakadate, attending the conference, was greatly impressed with the spectacle and decide to prolong his stay in Paris until the following year. During this time he studied developments in aviation amongst European countries before returning to Japan.

In Japan he constructed a wind-tunnel in his laboratory and began his own study of aeromechanics. In 1910, he was persuasive in his efforts to have Tokorozawa selected as the site for Japan's first airport. Later in 1918, he set about a department of aviation added to Tokyo University. For these and other efforts, he is recognized as the father of aviation in Japan.

League of Nations' Committee to Promote Intellectual Co-operation

Dr. Tanakadate was a member of the committee from 1927 until 1933, participating in the annual meetings held in Geneva. Marie Curie and Albert Einstein were also among the twelve members chosen from around the world. Committee members included other winners of the Nobel Prize with whom Tanakadate undoubtedly discussed aspects of science, technology, world peace, and international brotherhood. He was a noted linguist.

On November 23, 1938, on the fortieth anniversary of the discovery of radium (by Curie), Tanakadate delivered a congratulatory message to the French via broadcast from Japan.

A Distinguished Career

From 1898, Dr. Tanakadate journeyed to Europe no less than twenty-three times in addition to visits made for study-purposes. He attended a total of sixty-eight international conferences. It is for his enthusiasm and sense of purpose that Dr. Guillaume expressed his admiration (refer opening page).

In 1928, Dr. Tanakadate received the Legion of Honour from the French government for his contribution to aviation. This was followed by the Order of Cultural Merit from his own government in 1944.

Dr. Tanakadate passed away at the age of ninety-six on May 21, 1952. He is buried in his birth-place of Ninohe City, Iwate Prefecture. His name is inscribed in roman letters on his headstone. With his constant and diligent efforts throughout his long life, he made an outstanding and highly-respected contribution to teaching, technology, and cultural understanding, which will be long-remembered.


Satio Tanno
President, Aikitu Tanakadate Society
August 31, 1995
Society Address: 80-1, Nagamine, Hukuoka, Ninohe City


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