How do we know that the earth has a solid inner core?

Answer 1

It doesn't - the inner core is mostly molten iron.

Answer 2

Seismic measurements show that the core is divided into two parts, a solid inner core with a radius of ~1220 km and a liquid outer core extending beyond it to a radius of ~3480 km. The solid inner core was discovered in 1936 by Inge Lehmann and is generally believed to be composed primarily of iron and some nickel. Some have argued that the inner core may be in the form of a single iron crystal.[3] The liquid outer core surrounds the inner core and is believed to be composed of iron mixed with nickel and trace amounts of lighter elements. It is generally believed that convection in the outer core, combined with stirring caused by the Earth's rotation (see: Coriolis effect), gives rise to the Earth's magnetic field through a process described by the dynamo theory. The solid inner core is too hot to hold a permanent magnetic field (see Curie temperature) but probably acts to stabilise the magnetic field generated by the liquid outer core.

Answer 3

We know the Earth has a solid inner core because of the way vibrations behave when they pass through the Earth.
We know the Earth has a liquid outer core because of our magnetic field

Answer 4

inner core is 2270 km thick.secondary waves cannot pass through outer core, therefore we know the outer core is liquid (molten).
aprt from this composition of the inner core is : Molten Fe (85%) with some Ni, based on studies of composition of meteorites.
Core may also contain lighter elements such as Si, S, C, or O.

Convection in liquid outer core plus spin of solid inner core generates Earth's magnetic field.
Magnetic field is also evidence for a dominantly iron core.

Answer 5

Due to the "EXTREME" pressure being applied by the "overburden" NOTHING could be a liquid.

Take a few Physics Courses it will come to you LOL ;-)

Answer 6

the trolls told me so

Answer 7

It doesn't.