How was the asthenosphere discovered?

Answer 1

Although its presence was suspected as early as 1926, the worldwide occurrence of the asthenosphere was confirmed by analyses of earthquake waves from the Great Chilean Earthquake of May 22, 1960.

Answer 2

The asthenosphere was discovered through seismic studies in the early 20th century. By examining how seismic waves travel through the Earth, scientists found a low-velocity zone beneath the rigid lithosphere, indicating a partially molten layer that allows tectonic plates to move.