I had intended for this to be a weekly post, but we are really spoilt for choice! Today is the 127th birthday of Inge Lehmann. Lehmann was born in Denmark, and in her formative years was educated in a progressive school, led by the aunt of one Niels Bohr. She studied mathematics at the University of Copenhagen and University of Cambridge, but left her studies due to ill health and worked in offices for the next few years. Here, her computational skills were developed. She returned to her studies in 1918 to complete a degree in physical science and mathematics. After a brief stint as an actuarial scientist (fiscal jazz), she became an assistant to the geodesist Niels Erik Nørlund.
In this role she set up several seismological observatories in Denmark and Greenland, and in this time greatly increased her interest and knowledge in the area of seismology. Lehmann was the first to interpret P waves (primary seismic waves) as reflections from an inner core. This work was instrumental in the understand of the layers of the earth beneath our feet. She also collaborated Maurice Ewing and Frank Press on investigations of Earth’s crust and upper mantle, where she discovered the Lehmann discontinuity.
Lehmann was often frustrated by the negative attitudes and challenges she faced as a female scientist. Speaking to science historian Stephen G Brush in an interview in 1980 she commented on her progressive education and how it influenced her: “No difference between the intellect of boys and girls was recognised, a fact that brought some disappointments later in life when I had to recognise that this was not the general attitude.” The opening quote of this post was said to her nephew, according to the American Museum of National History.
Her nephew, Niels Groes, also told of her early computational methods. Lehmann would use empty oatmeal boxes to store memo cards with information about seismological events- an early precursor to databases we use today.
When she was honoured for the William Bowie medal (the highest honour of the American Geophysical Union) for the discovery of the Lehmann discontinuity Francis Birch noted that the “Lehmann discontinuity was discovered through exacting scrutiny of seismic records by a master of a black art for which no amount of computerization is likely to be a complete substitute.” Lehmann has truly left her mark, despite the challenges she experienced as a female scientist. She died at the age of 105 in 1993 in Copenhagen, Denmark.
Image: “Inge Lehmann 1932” by Unknown – http://www.kb.dk/images/billed/2013/apr/tilsalg/object11164/da/. Licensed under Public Domain via Wikimedia Commons.