Inge Lehmann, Danish Geophysicist and Seismologist (1888-1993)

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.

Inga Lehmann.Wikipedia (website).  Accessed 28 December 2021.