Is the core of the Earth solid or liquid?
Submitted by Michel Darche on
Using the anomalies in the propagation of seismic waves detected by analysing seismic data recorded by seismographs around the world, the Danish mathematician Inge Lehmann showed in 1936 that the liquid core of the Earth contains a solid inner core of radius 1,200km. Despite a temperature above 5000° C, the inner core becomes solid because of the pressure, which is more than 3.5 millions stronger at a depth of 5000 km than on the surface.
