Earth's solid inner core results from the fact that the
A) outer core is heated and melted by friction between the core and the mantle, and this heating does not extend to the inner core.
B) melting temperature of an iron-nickel mixture increases with increasing pressure and rises above the actual temperature in the inner core.
C) inner core has a different composition than the outer core, with a higher melting temperature.
D) temperature of the inner core is lower than the temperature of the outer core, producing a temperature inversion.

Question

Quizplus · Accepted Answer

The Earth's solid inner core results from the fact that the melting temperature of an iron-nickel mixture (which the core is primarily composed of) increases with increasing pressure. This pressure is so high in the inner core that it raises the melting point above the actual temperature present there, thus keeping the inner core solid despite the high temperatures.

Earth's Solid Inner Core Results from the Fact That the