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LITHOEN

Earth layer

Inner core

The solid innermost region of Earth’s core. Its solidity is an inference from the behaviour of seismic waves rather than a direct observation, and the reasoning behind that inference has itself been revised.

Classification

division basis
compositional

How this record is known

2
Settled consensus
Cited as the accepted position of the discipline.
1
Interpretation
Reached by reasoning from evidence, or produced by a named model.

3 of 3 claims on this page cite at least one registered source. Counts describe how each statement is known, not how likely it is to be true.

What Lithoen records

Each claim states how it is known and cites its evidence.

EstablishedThe decisive direct shear-wave phases through the inner core were not reliably observed.

The body-wave phases that would settle inner-core solidity directly — PKJKP, SKJKS, SKJKP, which travel through the inner core as shear waves — had not been reliably observed at the time the normal-mode inference was published.

Evidence support: Supported by the cited evidence one source

Evidence: Dziewonski 1971 Peer-reviewed

InferredSolid — it transmits shear energy.

The inner core is solid. Because it transmits shear energy where the outer core does not, it is taken to be solid rather than liquid.

  • method: Normal-mode observations and the behaviour of shear energy in the innermost core.
  • precision note: The inference was historically contested: it originally rested on an assumption about composition, and the direct body-wave phases that would settle it were long unobserved.

Evidence support: Supported by the cited evidence 2 sources, multiple sources, independence unknown

Evidence: EarthScope Consortium (NSF SAGE) n.d. Institutional reference; Dziewonski 1971 Peer-reviewed

Established1,250 km

The solid inner core is about 1,250 kilometres thick.

  • precision note: As stated by the source; this is a radius-like thickness for the innermost region, not a diameter.

Evidence support: Supported by the cited evidence one source

Evidence: Kious 1996 Primary authority

In the knowledge graph

Record last updated 2026-09-06. Corrections follow the published corrections policy; superseded claims are retained, never silently edited.