Inge Lehmann's paternal grandfather laid out the first Danish telegraph line (1854) and her great-grandfather was Governor of the National Bank.

[7] Lehmann's parents enrolled both her and her sister at Fællesskolen in 1904, a liberal and progressive school that offered the same curriculum to both boys and girls, a practice uncommon at the time.

[7] This school was led by Hanna Adler, Niels Bohr's aunt, a pioneering woman scholar and firm believer in gender equality.

Women were prohibited from working in universities at the time, and the vast majority of female college graduates searched for employment as elementary schoolteachers despite obtaining degrees that allowed them to teach at the upper-secondary (high school) level.

There, Lehmann faced gender-based adversities, not being allowed to fully participate in her studies, nor to achieve higher positions of education.

[7] She developed good computational skills in an actuary office she worked in for a few years until she resumed her studies at Copenhagen University in 1918.

She broke off an engagement in March 1917 and decided to remain unmarried, in order to pursue an academic career, which was not an unusual choice at the time.

She was chosen as a delegate for Denmark to attend the International Union of Geodesy and Geophysics in 1927—a role she filled another eight times over the next forty years.

She analyzed the seismic data from the earthquake and noticed that there were waves of significant amplitude recorded in the Russian cities of Sverdlovsk and Irkutsk, both unexpected locations.

They were unexpected locations due to the theory that S-waves and some P-waves are deflected by the core creating a shadow area in which waves are not able to pass through.

She published these findings in a paper titled P′ (1936),[17][18] Prior to 1936, scientists believed that the Earth's core was a single, massive molten sphere.

[21][14] She retired from her position as head of the Geodætisk Institut's seismological department in 1953, giving her more time to conduct research over the following decades.

[22] During the 1960s, Lehmann was able to explore more of the Earth using new technologies made specifically for detecting nuclear bombs during the Cold War.

While in the United States, Lehmann collaborated with Maurice Ewing and Frank Press on investigations of the Earth's crust and upper mantle.

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.

Her groundbreaking work provided the basis for modern seismic imaging techniques, which have become essential for exploring Earth's interior and monitoring nuclear tests.

[31][32] A memorial dedicated to Lehmann was installed on Frue Plads in Copenhagen on 15 May 2017, designed by Danish artist, Elisabeth Toubro.