Inge Lehmann was born on Copenhagen, Denmark on May 13, 1888. She attended at Copenhagen University where studied maths, physics, chemistry and astronomy. After pass her exams, Lehmann spent a year at Cambridge University.
In 1911, she returned to Copenhagen and worked for an insurance company. Eight years later, Lehmann returned to the University and in 1920 earned a degree in Mathematics.
Her interest in seismology began in 1925 while she was working at the Royal Danish Geodetic Institute. She became head of the Institute in 1928, and held that place until 1953.
When a large earthquake affected New Zealand, on 16 June 1929, Lehmann studied the shock waves and made an amazing discovering: some P-waves, which should have been deflected by the core, were in fact recorded at seismic stations. Lehmann interpreted that the waves was bounced off for some kind of boundary. In 1936, using this information, Lehmann published her paper entitled just “P’”. In this paper, Lehmann suggested that the center of the Earth is composed of two distinct parts: a solid inner core and a liquid outer core surrounding it, both separated by a discontinuity. It was not until 1970, that Lehmann’s hypothesis was confirmed, and the discontinuity was named after her.
Lehmann, who once referred to herself as the “the only Danish seismologist,” made a vast contribution to the understanding of the internal structure of Earth. In 1971, she was awarded AGU’s William Bowie Medal, the highest honor of the American Geophysical Union.
She died on February 21, at the age of 104. In 1997 the American Geophysical Union established the Inge Lehmann Medal to recognize “outstanding contributions to the understanding of the structure, composition, and dynamics of the Earth’s mantle and core”.