How does the 'hell well' deepest on the ground appear?

The world's deepest hole is now covered only with a rusty metal lid.

Do you know how deep the deepest artificial hole on the ground? The deepest Mariana Trench in the world has a maximum depth of 10,971km. The deepest man-made hole on land, located on Russia's Kola peninsula, is more than 12km deep.

The project to dig a hole called "Kola Super Deep Hole " was started in 1970 to understand the components of the Earth's crust. The initial goal of the project was to drill to a depth of 15 km underground.

Compare the depth of the Kola pit with many famous places such as the Mariana Trench, Mount Everest or the tallest building in the world Burj Khalifa.(Photo: Bored Therapy).

When the drill was brought underground, Russian engineers divided it into three drills to different depths. The deepest tip, named SG-3, reached a depth of 12.26 km in 1989. Their plan is to continue drilling to a depth of 13.5 km by the end of 1990, and reaching the goal of 15 km by the end of the year. 1993.

However, by 1992 scientists could not continue. The reason is that the temperature at a depth of 12km has reached 180 degrees C. If continuing to dig to the target of 15km, the temperature there can reach nearly 300 degrees Celsius, which will certainly destroy all drilling equipment.

Although not reaching the intended depth, scientists still discover many interesting things about the Earth's crust. They found that at a depth of 12 km underground there is still water, which was previously thought to be impossible. Gases such as helium, hydrogen, nitro and even CO ₂ were also detected during drilling.

They also discovered 24 new unicellular species, unearthing rocks from 2.7 billion years ago. The discovery of organisms at depths of 7km underground opens the assumption that living things can withstand pressure as well as hot temperatures to adapt in the ground.

The world's deepest hole is now covered with a sealed metal lid.(Photo: Rakot13).

Despite stopping drilling in 1992, the Kola project remained in place until 2005. By 2008, the facilities were dismantled, leaving only ruined buildings.

Above the Kola bore today is a metal lid with a diameter of 23cm that has rusted and been sealed. According to ABC, if one can fall into this hole, it will take 3-4 minutes to reach the bottom. Locals said the pit was so deep that it was named a "hell well".

Although unable to reach its original goal, the Kola wormhole has shown what limits humans can reach in their scientific research journey.

Kola Crater is still the deepest pit on land , but this depth has been surpassed at sea. In 2008, Qatar dug a hole 12,289km into the Al Shaheen oil field. In 2011, the Sakhalin-I project dug a 12,376km deep hole into the waters off Russia's Sakhalin island.

• Hear the underground sound from the Kola pit