Richard Dixon Oldham
Encyclopedia
Richard Dixon Oldham FRS (31 July 1858 – 15 July 1936) was a British geologist who made the first clear identification of the separate arrivals of P-wave
s, S-wave
s and surface waves on seismogram
s and the first clear evidence that the Earth has a central core.
, a Fellow of the Royal Society and geologist, Oldham was educated at Rugby School
and the Royal School of Mines
.
In 1879 Oldham became an assistant-superintendent with the Geological Survey of India
, working in the Himalayas
. He wrote about 40 publications for the Survey on geological subjects including hot springs, the geology of the Son Valley and the structure of the Himalayas and the Ganges plain. His most famous work was in seismology. His report on the 1897 Assam earthquake went far beyond reports of previous earthquakes. It included a description of the Chedrang fault, with uplift up to 35 feet and reported accelerations of the ground that had exceeded the Earth's gravitational acceleration. His most important contribution to seismology was the first clear identification of the separate arrivals of P-wave
s, S-wave
s and surface waves on seismogram
s. Since these observations agreed with theory for elastic waves, they showed that the Earth could be treated as elastic in studies of seismic waves.
In 1903, Oldham resigned from the GSI in 1903 due to ill-health and returned to the United Kingdom, living in Kew
and various parts of Wales
. In 1906 he wrote a paper analyzing seismic arrival times of various recorded earthquakes. He concluded that the earth had a core and estimated its radius to be less than 0.4 times the radius of the Earth.
In 1908 he was awarded the Lyell Medal
, in 1911 made a Fellow of the Royal Society, and from 1920 to 1922 served as the President of the Geological Society of London
, dying on 15 July 1936.
P-wave
P-waves are a type of elastic wave, also called seismic waves, that can travel through gases , solids and liquids, including the Earth. P-waves are produced by earthquakes and recorded by seismographs...
s, S-wave
S-wave
A type of seismic wave, the S-wave, secondary wave, or shear wave is one of the two main types of elastic body waves, so named because they move through the body of an object, unlike surface waves....
s and surface waves on seismogram
Seismogram
A seismogram is a graph output by a seismograph. It is a record of the ground motion at a measuring station as a function of time. Seismograms typically record motions in three cartesian axes , with the z axis perpendicular to the Earth's surface and the x- and y- axes parallel to the surface...
s and the first clear evidence that the Earth has a central core.
Life
Born on 31 July 1858 to Thomas OldhamThomas Oldham
Thomas Oldham was a Anglo-Irish geologist.He was educated at Trinity College, Dublin and studied civil engineering at the University of Edinburgh as well as geology under Robert Jameson....
, a Fellow of the Royal Society and geologist, Oldham was educated at Rugby School
Rugby School
Rugby School is a co-educational day and boarding school located in the town of Rugby, Warwickshire, England. It is one of the oldest independent schools in Britain.-History:...
and the Royal School of Mines
Royal School of Mines
Royal School of Mines comprises the departments of Earth Science and Engineering, and Materials at Imperial College London.- History :The Royal School of Mines was established in 1851, as the Government School of Mines and Science Applied to the Arts...
.
In 1879 Oldham became an assistant-superintendent with the Geological Survey of India
Geological Survey of India
Geological Survey of India , established in 1851 is a government organization in India which is an attached office to the Ministry of Mines of Union Government of India for conducting geological surveys and studies. It is one of the oldest of such organizations in the world and the second oldest...
, working in the Himalayas
Himalayas
The Himalaya Range or Himalaya Mountains Sanskrit: Devanagari: हिमालय, literally "abode of snow"), usually called the Himalayas or Himalaya for short, is a mountain range in Asia, separating the Indian subcontinent from the Tibetan Plateau...
. He wrote about 40 publications for the Survey on geological subjects including hot springs, the geology of the Son Valley and the structure of the Himalayas and the Ganges plain. His most famous work was in seismology. His report on the 1897 Assam earthquake went far beyond reports of previous earthquakes. It included a description of the Chedrang fault, with uplift up to 35 feet and reported accelerations of the ground that had exceeded the Earth's gravitational acceleration. His most important contribution to seismology was the first clear identification of the separate arrivals of P-wave
P-wave
P-waves are a type of elastic wave, also called seismic waves, that can travel through gases , solids and liquids, including the Earth. P-waves are produced by earthquakes and recorded by seismographs...
s, S-wave
S-wave
A type of seismic wave, the S-wave, secondary wave, or shear wave is one of the two main types of elastic body waves, so named because they move through the body of an object, unlike surface waves....
s and surface waves on seismogram
Seismogram
A seismogram is a graph output by a seismograph. It is a record of the ground motion at a measuring station as a function of time. Seismograms typically record motions in three cartesian axes , with the z axis perpendicular to the Earth's surface and the x- and y- axes parallel to the surface...
s. Since these observations agreed with theory for elastic waves, they showed that the Earth could be treated as elastic in studies of seismic waves.
In 1903, Oldham resigned from the GSI in 1903 due to ill-health and returned to the United Kingdom, living in Kew
Kew
Kew is a place in the London Borough of Richmond upon Thames in South West London. Kew is best known for being the location of the Royal Botanic Gardens, now a World Heritage Site, which includes Kew Palace...
and various parts of Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
. In 1906 he wrote a paper analyzing seismic arrival times of various recorded earthquakes. He concluded that the earth had a core and estimated its radius to be less than 0.4 times the radius of the Earth.
In 1908 he was awarded the Lyell Medal
Lyell Medal
The Lyell Medal is a prestigious annual scientific medal given by the Geological Society of London, equal in status to the Murchison Medal, awarded on the basis of research to an Earth Scientist of exceptional quality...
, in 1911 made a Fellow of the Royal Society, and from 1920 to 1922 served as the President of the Geological Society of London
President of the Geological Society of London
The President of the Geological Society of London is the President of the Geological Society of London.- List of presidents :* 1807 - 1813 George Bellas Greenough* 1813 - 1815 Henry Grey Bennet* 1815 - 1816 William Blake* 1816 - 1818 John MacCulloch...
, dying on 15 July 1936.
See also
- Harold JeffreysHarold JeffreysSir Harold Jeffreys, FRS was a mathematician, statistician, geophysicist, and astronomer. His seminal book Theory of Probability, which first appeared in 1939, played an important role in the revival of the Bayesian view of probability.-Biography:Jeffreys was born in Fatfield, Washington, County...
– showed that the outer coreOuter coreThe outer core of the Earth is a liquid layer about 2,266 kilometers thick composed of iron and nickel which lies above the Earth's solid inner core and below its mantle. Its outer boundary lies beneath the Earth's surface...
is liquid - Inge LehmannInge LehmannInge Lehmann FRS , was a Danish seismologist who, in 1936, argued that the Earth's core is not one single molten sphere, but that an inner core exists which has physical properties that are different from those of the outer core.-Life:Inge Lehmann was born and grew up in Østerbro, a part of...
– showed that the inner coreInner coreThe inner core of the Earth, its innermost hottest part as detected by seismological studies, is a primarily solid ball about in radius, or about 70% that of the Moon...
is solid - List of geophysicists