Milne J
ACHIEVEMENT(S): As well as inventing a seismograph, he started seismological stations.
DATE/PLACE OF BIRTH: 30th December 1850, in Liverpool, England.
DATE/PLACE/AGE AT DEATH: 30th July 1913, in Shide, England. Aged 62.
DISCIPLINE: Seismologist and geologist.
FIELD: Seismology.
LANGUAGE: English.
PARENTS: John Milne and Emma Twycross.
SIBLINGS: None.
SPOUSE: Tone Horikawa, married 1881.
CHILDREN: None.
EDUCATION: Liverpool College; King's College, University of London; Royal College of Mines.
MAJOR WORK: 'Earthquakes and Other Earth Movements'(with W.K. Burton),1886.
LIFE AND TIMES: In 1871, Milne made an expedition to the Vatnajokull seismically-active area in Iceland.
In England he worked in mines in Cornwall and Lancashire. He then went to Freiburg in Germany, where he studied mineralogy from 1872 to 1873. Later in 1873, he went to Canada, visiting Newfoundland and Labrador to study the mineral resources there. The following year, now an experienced geologist, he went to north-western Arabia and Egypt, on an expedition to find the exact position of Mount Sinai.
In 1875, Milne took the position of professor of geology and mining at the Imperial College of Engineering in Tokyo, a job that was to dominate the rest of his working life. In Japan, he began a comprehensive study of volcanoes and earthquakes.
Following the work of Irish seismologist, Mallet*, Japanese geologists had begun to study and analyse earthquakes and Milne decided to channel his energies in that direction. An earthquake in February 1880, near Yokohama, prompted him to propose the creation of a Seismological Society of Japan, devoted exclusively to the study of earthquakes and volcanoes.
During the 1880s, Milne and two colleagues, Thomas Gray and Sir James Alfred Ewing, who were both engineering professors, set about constructing precise devices using pendulums. By 1892, they had developed the reliable horizontal pendulum seismograph*. Their design was used to record horizontal ground movement, until the Russian physicist, Boris Golitsyn*, superseded it with his electromagnetic seismograph in 1906.
Milne’s seismograph was simple enough to be installed on a global basis. By providing world-wide recording of ground movements, the system showed that earthquakes struck in waves that move, not only backwards and forwards, as Milne had expected, but also from side to side, and up and down as well. Milne was able to detect different types of earthquake waves, and estimate wave velocities.
From his Tokyo records, Milne found that, in large earthquakes, the ground accelerations were comparable with the vertical acceleration of gravity and he showed that such accelerations were generally greater, and therefore more dangerous, on soft ground than on hard rock. In his research, Milne set up thousands of experiments involving explosions, adding hugely to the pool of knowledge of seismic effects.
Milne obtained records showing groups of waves corresponding to the primary and secondary waves of modern seismology and, by 1900, he had plotted the first significant travel-time curves for primary, secondary and surface waves to spread of 160 degrees.
Prior to this time, Milne, in collaboration with W K Burton, had written a textbook 'Earthquakes and Other Earth Movements', published in 1886, which he followed up twelve years later with 'Seismology'. He was made a Fellow of the Royal Society* in 1887 and received the Lyell Medal of the Geological Society, London, in 1894.
On 17th February 1895, a fire destroyed Milne's home in Tokyo as well as his observatory, library and many of his instruments. Despite being awarded the Order of the Rising Sun by the Japanese Emperor, Milne resigned from the Imperial University. By this time, there were almost 700 stations for observing earthquakes across Japan, but Milne decided to return to England.
In June 1895, he settled in Shide Hill House on the Isle of Wight, where he set up a laboratory. Milne talked the Royal Society into financing a chain of earthquake observatories around the world, all equipped with his seismographs. The network, with its centre on the Isle of Wight, included seven stations in England, three in Russia, one in British Columbia, three on the East coast of the United States and one in Antarctica.
Eventually, the chain numbered forty observatories, carrying out continuous seismic surveillance in a global network. From the data collected, Milne produced his "Shide Circulars", which were the forerunners of the 'International Seismological Summary' which, after his death, became the basic source of instrument-gathering data on earthquakes.
ASSESSMENT: John Milne was possibly the greatest individual contributor to observational earthquake investigations and the field of seismology.
EXTRA CONNECTIONS: None.
ONELINER: John Milne, founder of first seismic network
BIBLIOGRAPHY:
Herbert-Gustar, L.K. and P. Nott, John Milne: Father of Modern Seismology, London, 1980.
Verney, Peter, The Earthquake Handbook, New York & London, 1979.