On 13th May, 1888 Inge Lehmann was born. She was a Danish seismologist who, in 1936, proposed that the centre of the Earth consisted of both an Inner and Outer Core, both of different compositions. This decision was widely accepted by seismologists who were previously unable to explain why P-waves slowed down as they reached the centre of the Earth.
In the 1950s the Lehmann Discontinuity, which describes the increase in P- and S-wave velocities at about between 190 - 250km, was named after her when she discovered it.
Her pioneering research has allowed seismic research to continue to leap forward today, and her theory on the Earth's core is still valid today. She passed away in 1993, ending a good innings of 104 years, but her legacy still lives on. The American Geophysical Union named a medal in her honour for "Outstanding contribution to the understanding of structure, composition and dynamics of the Earth's core and mantle."
We thank her for her contribution to science and hope that her legacy continues to live on.