Inge Lehmann

Inge Lehmann ForMemRS (May 13, 1888 – February 21, 1993) was a Danish seismologist and geophysicist who discovered the Earth’s inner core. In 1936, she postulated from existing seismic data that the Earth’s core is not a single molten sphere, but that an inner core exists, which has physical properties that are different from those in the outer core. This conclusion was quickly accepted by seismologists, who up to this time had not been able to propose a workable hypothesis for the observation that the P-wave created by earthquakes slowed down when it reached certain areas of the inner Earth.