Why do scientists believe part of the Earth's core is liquid?

Question

A. Earths oceans are liquid
B. Earth has an atmosphere
C. Earth has a magnetic field
D.Earths moon causes oceanic tides

Answer 1

During earthquakes you can Analise the seismograph recorded at that place to know the inner parts of earth. The primary wave will pass through liquid.But the secondary wave will get reflected when it touches the liquid surfaces.There are several waves other than P,S,L,& R like pp,ss,ps can be seen in the graph that the seismiologist can distingush.

Answer 2

The Earth is not a blob of liquid. The thin outer crust sits on the solid mantle, which is 2900 km thick. The liquid outer core beneath the mantle is 2255 km thick, and the solid inner core is 1215 km in diameter. Therefore, and ignoring the thin crust, the liquid outer core comprises only 35% of the Earths diameter. But even if the Earth were largely liquid it would still retain the shape of a globe under the force of gravity, albeit it would be more easily deformed by the centrifugal force of its spin and by the tidal pull of the Sun and other massive objects in the Solar System. The situation of a planet composed of volatile materials is realized in the cases of Jupiter, Saturn and the other giant planets. Jupiter is composed mainly of hydrogen and helium, which is a gas in the outer regions of the planet and probably a metallic liquid at the enormous pressures in its interior. Jupiter keeps its shape because
the enormous force of gravity pulls all of its matter towards the centre.

Answer 3

Well, out the answers given you want to go with C, though its not a very good question or rather a good question but with a bad set of answers to choose from.

Sir Harold Jeffreys proposed a liquid outer core when he noted that S-waves traveling through the Earth stop at a certain point while P-waves continue at a different velocity. S-waves do not propagate through liquid.

Inge Lehmann further discovered that the inner core was solid after noting that P-waves make yet another velocity change. After her work, we have divided Earth into 4 layers: crust, mantle, outer core (liquid), inner core (solid).

The circulation of the outer core is thought to be responsible for the Earth's magnetic field.

Answer 4

Magnetic feilds play a small part in it, but it's all liquid in the very core. The geothermal heat melts the rock, not gravity, or magnetism.

Answer 5

Because the oceans are liquid. Hey, all that water must've come from somewhere!