Scientific method
The study of seismic waves generated by earthquakes and other sources. Because the waves travel through the whole planet and change character at every boundary they cross, seismology is the principal means by which Earth’s interior is known at all.
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.
Each claim states how it is known and cites its evidence.
A seismograph has a base set firmly in the ground and a heavy weight hanging free; when the ground shakes the base moves but the weight does not, and the difference between the shaking and motionless parts is what is recorded.
Evidence support: Supported by the cited evidence 2 sources, multiple sources, independence unknown
Evidence: Wald n.d. Primary authority; U.S. Geological Survey n.d. Primary authority
Nothing in Earth’s deep interior has been observed directly. What is recorded is ground motion at the surface; everything below the shallowest crust is reconstructed from how waves behave on the way.
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
Earthquakes create seismic waves that travel through the whole Earth; seismologists read the recordings of ground motion those waves produce to explore the deep interior.
Evidence support: Supported by the cited evidence 2 sources, multiple sources, independence unknown
Evidence: EarthScope Consortium (NSF SAGE) n.d. Institutional reference; Wald n.d. Primary authority
Record last updated 2026-09-06. Corrections follow the published corrections policy; superseded claims are retained, never silently edited.