The main way that scientists have been able to determine the makeup of the interior of the Earth is by studying how seismic waves pass through its various layers. In addition, they have also made theories about the composition of the core of the Earth by studying its magnetic fields.Continue Reading
Scientists know that shear seismic waves, such as those produced by earthquakes, cannot properly travel through liquid. When an earthquake occurs on earth, scientists are able to measure these waves for some time, until they reach the earth's inner core. As the waves disappear when they reach the inner core, scientists have been able to determine that it is composed of liquid. However, the waves then reappear after some time, leading scientists to theorize that the outer core must be made of liquid, while the inner core is a solid.
Still, these seismic waves only provide information about the state of the various layers and not of what they are composed. However, by studying the magnetic fields of the Earth, scientists have also been able to determine that both the inner and outer cores are composed primarily of iron, as the planet would not be able to have a magnetic field if this were not the case.Learn more about Layers of the Earth
The four layers of the Earth are called the inner core, the outer core, the mantle and the crust. In addition, there are two different types of crust. The continental crust is the part that is under land, and the oceanic crust is the part under the oceans.Full Answer >
According to Indiana University, geologists observe the Earth's interior by using seismic waves to determine the depths of layers of molten and semi-molten material within Earth. Seismic stations positioned around the world record the strength of different types of waves in order to establish the structure of Earth's interior.Full Answer >
As of April 2013, scientists have recorded the temperature in the center of the Earth to be 6,000 degrees Celsius. This is 1,000 degrees hotter than the measurement previously recorded from an experiment run 20 years prior.Full Answer >
The key characteristics of the Earth's layers are the thinness of the crust, the rigidity of the upper mantle and the viscosity of the lower mantle and the asthenosphere. Other characteristics are the liquid state of the outer core, and the great heat and pressure of the inner core.Full Answer >