Humans have no direct means to know the interior structure of the Earth. Human knowledge about the structure of this part is limited to very little depth. Direct knowledge of the structure of the earth can be found only by oil wells, mines to the depth of only 3 to 4 km in most places. It is very minuscule compared to the depth of the center of the Earth (about 6371 km).
By mining activity, we learn that as the depth of the Earth’s surface increases, the temperature and pressure also increase. According to an estimate, the temperature of the inner part of the Earth is approximately 2000°C. Due to such high temperature, it is completely impossible to obtain direct knowledge of the earth’s internal structure.
Therefore, direct study of the interior structure of the Earth is beyond the human capability. With this reason, for obtaining information about the interior part of the earth, man is dependent on indirect sources, like earthquakes, seismic waves, temperature, pressure, meteorites and gravity.
