Motonori Matuyama
Encyclopedia
was a Japanese
geophysicist
who was the first to surmise that the Earth's magnetic field
had undergone reversals in the past. The era of reversed polarity preceding the current Brunhes era of normal polarity is called the Matuyama reversed chron and the boundary between them is called the Brunhes–Matuyama reversal.
, the son of a Zen
abbot
. He was educated at the University of Hiroshima and Kyoto Imperial University
, where he was appointed to a lectureship in 1913. After spending the period 1919–21 at the University of Chicago
working with Thomas C. Chamberlin he was made professor of theoretical geology at Kyoto Imperial University. He conducted a gravity survey
of Japan during the period 1927–32, extending this to also cover Korea
and Manchuria
, and studied marine gravity using the Vening–Meinesz
pendulum apparatus in a submarine
.
While rocks had earlier been found with polarities opposite to the present field
and the hypothesis advanced that the field had reversed in the past, Matuyama was the first to conduct a disciplined study of the hypothesis. In 1926 he began collecting basalt specimens in Manchuria and Japan, and in 1929 published a paper showing that there was a clear correlation between the polarity and the stratigraphic
position. He remarked that in the early Pleistocene
the Earth's field had been reversed and that it had later changed to the present polarity. The period of reversed polarity, dating from , is now called the Matuyama reversed chron and the transition to normal polarity (like that of the present Earth's field) is the Brunhes-Matuyama reversal
.
This reversed polarity, particularly as shown by the rocks of the ocean floor
, was to provide crucial evidence for the sea floor spreading
hypothesis of Harry H. Hess
.
Japanese people
The are an ethnic group originating in the Japanese archipelago and are the predominant ethnic group of Japan. Worldwide, approximately 130 million people are of Japanese descent; of these, approximately 127 million are residents of Japan. People of Japanese ancestry who live in other countries...
geophysicist
Geophysics
Geophysics is the physics of the Earth and its environment in space; also the study of the Earth using quantitative physical methods. The term geophysics sometimes refers only to the geological applications: Earth's shape; its gravitational and magnetic fields; its internal structure and...
who was the first to surmise that the Earth's magnetic field
Earth's magnetic field
Earth's magnetic field is the magnetic field that extends from the Earth's inner core to where it meets the solar wind, a stream of energetic particles emanating from the Sun...
had undergone reversals in the past. The era of reversed polarity preceding the current Brunhes era of normal polarity is called the Matuyama reversed chron and the boundary between them is called the Brunhes–Matuyama reversal.
Life
Matuyama was born at Uyeda (now Usa) in JapanJapan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, the son of a Zen
Zen
Zen is a school of Mahāyāna Buddhism founded by the Buddhist monk Bodhidharma. The word Zen is from the Japanese pronunciation of the Chinese word Chán , which in turn is derived from the Sanskrit word dhyāna, which can be approximately translated as "meditation" or "meditative state."Zen...
abbot
Abbot
The word abbot, meaning father, is a title given to the head of a monastery in various traditions, including Christianity. The office may also be given as an honorary title to a clergyman who is not actually the head of a monastery...
. He was educated at the University of Hiroshima and Kyoto Imperial University
Kyoto University
, or is a national university located in Kyoto, Japan. It is the second oldest Japanese university, and formerly one of Japan's Imperial Universities.- History :...
, where he was appointed to a lectureship in 1913. After spending the period 1919–21 at the University of Chicago
University of Chicago
The University of Chicago is a private research university in Chicago, Illinois, USA. It was founded by the American Baptist Education Society with a donation from oil magnate and philanthropist John D. Rockefeller and incorporated in 1890...
working with Thomas C. Chamberlin he was made professor of theoretical geology at Kyoto Imperial University. He conducted a gravity survey
Geophysical survey
Geophysical survey is the systematic collection of geophysical data for spatial studies. Geophysical surveys may use a great variety of sensing instruments, and data may be collected from above or below the Earth's surface or from aerial or marine platforms. Geophysical surveys have many...
of Japan during the period 1927–32, extending this to also cover Korea
Korea
Korea ) is an East Asian geographic region that is currently divided into two separate sovereign states — North Korea and South Korea. Located on the Korean Peninsula, Korea is bordered by the People's Republic of China to the northwest, Russia to the northeast, and is separated from Japan to the...
and Manchuria
Manchuria
Manchuria is a historical name given to a large geographic region in northeast Asia. Depending on the definition of its extent, Manchuria usually falls entirely within the People's Republic of China, or is sometimes divided between China and Russia. The region is commonly referred to as Northeast...
, and studied marine gravity using the Vening–Meinesz
Felix Andries Vening Meinesz
Felix Andries Vening Meinesz was a Dutch geophysicist and geodesist. He is known for his invention of a precise method for measuring gravity. Thanks to his invention, it became possible to measure gravity at sea, which led him to the discovery of gravity anomalies above the ocean floor...
pendulum apparatus in a submarine
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...
.
While rocks had earlier been found with polarities opposite to the present field
Earth's magnetic field
Earth's magnetic field is the magnetic field that extends from the Earth's inner core to where it meets the solar wind, a stream of energetic particles emanating from the Sun...
and the hypothesis advanced that the field had reversed in the past, Matuyama was the first to conduct a disciplined study of the hypothesis. In 1926 he began collecting basalt specimens in Manchuria and Japan, and in 1929 published a paper showing that there was a clear correlation between the polarity and the stratigraphic
Stratigraphy
Stratigraphy, a branch of geology, studies rock layers and layering . It is primarily used in the study of sedimentary and layered volcanic rocks....
position. He remarked that in the early Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
the Earth's field had been reversed and that it had later changed to the present polarity. The period of reversed polarity, dating from , is now called the Matuyama reversed chron and the transition to normal polarity (like that of the present Earth's field) is the Brunhes-Matuyama reversal
Brunhes-Matuyama reversal
The Brunhes–Matuyama reversal, named after Bernard Brunhes and Motonori Matuyama, was a geologic event, approximately 780,000 years ago, when the Earth's magnetic field last underwent reversal. The reversal may have occurred slowly over several thousand years, or more quickly; opinions vary...
.
This reversed polarity, particularly as shown by the rocks of the ocean floor
Seabed
The seabed is the bottom of the ocean.- Ocean structure :Most of the oceans have a common structure, created by common physical phenomena, mainly from tectonic movement, and sediment from various sources...
, was to provide crucial evidence for the sea floor spreading
Seafloor spreading
Seafloor spreading is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge. Seafloor spreading helps explain continental drift in the theory of plate tectonics....
hypothesis of Harry H. Hess
Harry Hammond Hess
Harry Hammond Hess was a geologist and United States Navy officer in World War II.Considered one of the "founding fathers" of the unifying theory of plate tectonics, Rear Admiral Harry Hammond Hess was born on May 24, 1906 in New York City...
.