In ancient myths, people often believed that the center of the Earth was hollow, stemming from early understandings of tunnels. However, modern science reveals that the Earth's interior is far more complex. Currently, the deepest oil well we can drill reaches only 9.6 kilometers, while the Earth's radius is about 6,350 kilometers. So, what lies at the core? Scientists have uncovered the Earth's three-layer structure through the study of seismic waves: the crust, the mantle, and the core.
The crust is the outermost layer, composed of familiar rocks. About 32 kilometers underground, the structure of the crust changes, forming the Mohorovičić discontinuity. Below that is the mantle, also made up of hard rocks. Further down, at a depth of around 2,900 kilometers, seismic waves change significantly, indicating that the core is liquid and primarily composed of iron and nickel, which make up 90% and 10% respectively. However, some researchers suggest that the core may also contain oxygen or sulfides, which remains an unsolved mystery.
As humanity continues to dig deeper into the Earth, temperatures gradually rise. In the quest for diamonds and gold, attempts have been made to penetrate deeper underground, but the rapid increase in temperature makes this process extremely challenging. It is estimated that the temperature at the core could reach up to 68,000 degrees Celsius, which is hard to imagine.
