ECONOM 1051 Lecture Notes - Hydrosphere
Document Summary
Earth"s layers- densest materials are at center, lightest form outer layer (result of gravity, similar for all planets). Inside out: core (liquid iron)iron rich sphere having a radius of 3,486 km. Earth"s dense central sphere: two parts, outer core - liquid outer layer about 2270 km thick. b. Inner core - solid inner sphere with a radius of 1216 km. discovery- by lehmann in 1936. P-wave shadow zone is not a perfect shadow-there are weak p waves arriving, lehmann suggests that"s formed from a solid iron core: density and composition: average density is nearly 11 g/cm3 and at. Earth"s center approaches 14 times the average density of water. Core rotates faster than earth"s surface; axis offset about ten degrees from earth"s poles: mantle (dense rock)- solid rock (silicon-rich) shell from 2900 km, contains 82% of earth"s volume. Upper portion has the composition of the ultramafic rock peridotite: two parts, asthenosphere or upper mantle- has composition of ultramafic rock peridotite.
