<P> The Earth was discovered to have a solid inner core distinct from its molten outer core in 1936 , by the Danish seismologist Inge Lehmann , who deduced its presence by studying seismograms from earthquakes in New Zealand . She observed that the seismic waves reflect off the boundary of the inner core and can be detected by sensitive seismographs on the Earth 's surface . This boundary is known as the Bullen discontinuity , or sometimes as the Lehmann discontinuity . A few years later , in 1940 , it was hypothesized that this inner core was made of solid iron ; its rigidity was confirmed in 1971 . </P>
<P> The Earth was discovered to have a solid inner core distinct from its molten outer core in 1936 , by the Danish seismologist Inge Lehmann , who deduced its presence by studying seismograms from earthquakes in New Zealand . She observed that the seismic waves reflect off the boundary of the inner core and can be detected by sensitive seismographs on the Earth 's surface . This boundary is known as the Bullen discontinuity , or sometimes as the Lehmann discontinuity . A few years later , in 1940 , it was hypothesized that this inner core was made of solid iron ; its rigidity was confirmed in 1971 . </P>
who discovered the inner core of the earth
who discovered the inner core of the earth
Inge Lehmann
Inge Lehmann