Discovered composition of Earth’s core. She theorized that the inner core was solid with a molten outer core surrounding it. Her thesis was not able to be proven until computers were utilized in 1971.
Educated at Copenhagen University and Cambridge, she interpreted seismic P-waves from earthquakes as indicative of the composition of the inner core. Later in her career, she discovered the step-change increase in seismic wave, depending on depths, commonly measured at 190 and 250 km. This discovery was named after her, as the Lehmann Discontinuity.
Sources:
“Inga Lehmann.” Wikipedia (website). Accessed 28 December 2021.