The Composition and Structure of Earth

The earth is made up of three different layers: the crust, the mantle and the core. This is the outside layer of the earth and is made of solid rock, mostly basalt and granite. There are two types of crust; oceanic and continental. Oceanic crust is denser and thinner and mainly com posed of basalt. Earth was discovered to have a solid inner core distinct from its molten outer core in 1936, by the Danish seismologist I. Lehmann, who deduced its presence by studying seismograms from earthquakes in New Zealand. ... The rigidity of the inner core was confirmed in 1971. The structure of the earth is divided into four major components: the crust, the mantle, the outer core, and the inner core. Each layer has a unique chemical composition, physical state, and can impact life on Earth's surface