The Search Engine Google is showing this animated Doodle on May 13th, 2015, for celebrating 127th Birthday of Inge Lehmann

Inge Lehmann was a Danish seismologist 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.

Inge Lehmann was born on May 13 th 1888 in Denmark and died in 1993.

At the age of 105, Inge Lehmann looked back on a long, productive life with satisfaction.

During her career in seismology, she had made two major discoveries and made other significant contributions.

Lehmann is first and foremost known as the discoverer of Earth's inner core in 1936, but she is also highly regarded for her studies of Earth's mantle, carried out during many visits to the United States in the 1950s and the 1960s. In these studies she identified a low velocity layer between 130 and 220 kilometers below Earth's surface. The bottom of this layer, at which the velocity of seismic waves rises abruptly, is now called the Lehmann disconti.