Answer:
Direct evidence from rock samples and indirect evidence from seismic waves may account for why scientists have two ways of thinking about earth's layers
Explanation:
Scientists who study about the earth's structure and components called geologists have two main types of evidence to learn about Earth's interior namely
1. direct evidence from rock samples
2. indirect evidence from seismic waves
Direct evidence From Rock Samples
Scientists examine rocks from inside the Earth and these rocks give them clues about Earth’s structure. Some scientists have drilled holes as much as 12 kilometers into Earth and bring up samples of rock. From these samples, they can make inferences about conditions deep inside Earth, where these rocks formed. In addition, forces inside Earth sometimes blast rock to the surface from depths of more than 100 kilometers. These rocks from deep within the Earth provide more information about the interior.
Indirect evidence From Seismic Waves
Since scientist cannot look inside Earth, they have devised an indirect methods of observation by using seismic waves. When earthquakes occur, they produce seismic waves. Scientists record the seismic waves and study how they travel through Earth. The speed of seismic waves and the paths they take reveal the structure of the planet. Using data from seismic waves, scientists have learned that Earth’s interior is made up of several layers with each layer surrounding the layers beneath it.
