Inner Core 1 : The central part of the Earth's core. It extends from a depth of about 5200 km to the Earth's center. It has non-zero rigidity, in contrast to the outer core and was discovered in 1936 by Inge Lehmann
Peter Bormann, Keiiti Aki, William H. K. Lee, and Johannes Schweitzer (Compilers and Amenders), Glossary of Terms Interest to Earthquake and Engineering Seismologists (Version 1), Publication records from external use of GFZ scientific infrastructure, Germany 2011. http://gfzpublic.gfz-potsdam.de/pubman/item/escido c:56137:3/component/escidoc:56143/Glossary_rev1.pd f, (ND/ Erthq - Amer) {980}