What’s the Deepest Hole Ever Dug on Earth (And How Deep Can We Go?)

Written by Emmanuel Kingsley
Updated: June 4, 2023
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Like most people, you probably attempted digging a deep hole to “the ends of the earth” as a child but gave up after a few inches after realizing just how hard and even boring it was. While having the time and tools to dig the deepest hole ever would not be boring, it definitely is hard and requires hours upon hours.

But say you had the time and could devote as many years as you’d like to digging – just how far could you go? Today, we’ll consider just how deep humans can dig and some of the deepest holes ever dug.

How Deep Is the Earth?

Black hole
The maximum anyone would want to dig to is the earth’s core which is its center.


Before we consider just how deep one can dig, it’s important to consider the limitations to digging or drilling. The maximum anyone would want to dig to is the earth’s core which is its center, and that is about 3,959 miles away from the earth’s surface. If anyone were to achieve this feat, they would be able to make the earth hollow, as they would only need to drill from the opposite side to the core to complete the hollow space.

While drilling to this point might be possible, it is impossible for humans to physically visit the earth’s core for several reasons, including temperature. Scientists estimate that the temperature in the earth’s inner core is about 9,392 degrees Fahrenheit (5,200 degrees Celsius), and considering that the maximum heat your body can take is about 108.14 degrees Fahrenheit, digging to this level or past it is not yet possible with the current level of human technology.

This doesn’t mean humans cannot be in temperatures higher than 108.14 degrees Fahrenheit. Modern-day technology enabled the invention of auxiliary cooling systems which allow humans to tolerate higher temperatures, but not temperatures as high as 9,392 degrees Fahrenheit, which is more than 5 times the melting point of gold and almost as hot as the surface of the sun.

However, there is another reason that you wouldn’t want to dig past the earth’s core to its crust, even if you could. Digging from one side of the earth’s crust to another would make the earth hollow, and as you probably know, hollow earth wouldn’t work. If the hole were small, gravity would cause a collapse which would close the hole and create a smaller sphere. And if the hole were a large one, gravity, and the atmosphere would be affected, which would cause us to fly off the Earth and into space. However, we wouldn’t make it into space without dying.

What Is the Deepest Hole Ever Dug?

the Kola Superdeep Borehole
The Kola Superdeep Borehole or the Kola Well is the deepest hole ever dug.


In 1970, members of Russia or the Soviet Union decided to dig the deepest hole ever in a bid to see just how deep they could go. To avoid damaging the earth’s infrastructure, they decided to dig a hole with a diameter of only nine inches (for reference, a jar of Nutella is a little less than three inches, so think three times as large), so falling into this hole is impossible – which is a relief, if we’re being honest.

Drilling began in 1970 and lasted until 1989 when the drill hit a depth with temperatures of 356 degrees Fahrenheit (180 degrees Celsius). This was more than two times what was expected, and as a result, drilling was unable to continue because the drills couldn’t work in such heat.

So, just how deep was this hole? The hole, which was named the “Kola Superdeep Borehole” or the “Kola Well” reached 12,262 meters (7.6 miles) deep, making it the deepest hole ever dug. The Kola Well is more than 14 times the size of Dubai’s Burj Khalifa, the tallest building in the world. This might sound like a lot, but in reality, it is less than 1/500 of the distance to the Earth’s core.

You might imagine that the drill wasn’t so large because of how insignificant the depth seems compared to the earth’s core, but this couldn’t be further from the truth. According to a 2021 study that reviewed how the hole was dug, a Uralmash-4E was used and later replaced with a specialized Uralmash-15000 drilling rig. The hole was dug using about 25 different drilling methods.

Where Is the Kola Superdeep Borehole Located on the Map?

The Kola Superdeep Borehole is located in Russia’s north, close to its border with Norway. It is located to the northwest of the city of Murmansk, and to the southwest of Pechenga. The former city remains delightfully ice-free in spite of its location and is home to several museums and art galleries.

What Is the Deepest Hole in the USA?

Washita County Courthouse
In Washita County in the state of Oklahoma, the Bertha Rogers gas well, the deepest hole ever dug in the USA, can be found.

©Jeffrey Beall / CC BY 3.0 – License

The deepest hole ever dug in the USA is in the state of Oklahoma, in Washita County. The “hole” is named Bertha Rogers gas well and is 9,583 meters (six miles) deep. It was ranked the deepest hole in the world before the Kola well was completed.

However, the Bertha Rogers gas well was dug in significantly less time than the Kola well. Drilling started in 1972, two years after the Soviet Union started its project. It progressed much faster, and in a year and a half, the hole was already six miles deep.

But unlike the Kola well, which was continued for two decades, the immense pressure that the well encountered caused them to abandon the project. The drill hit a molten sulfur deposit which damaged the drill and effectively halted further work. Consequently, the hole was plugged and the site was abandoned.

Could Humans Dig Deeper Than the Kola Well?

underground tunnel
With the advancement of technology, humans should be able to dig a hole deeper than the Kola well.


When the Kola well project began, technology was nowhere as advanced as it now is. For example, the internet was first made public in 1993, four years after drilling stopped. It’s been 33 years since drilling stopped and 52 years since it started, technology has significantly advanced since then. This means that humanity has more knowledge and tools and would be able to progress a lot more than we did 50 years ago.

In fact, a startup company named Quaise Energy recently secured $40 million in funding after pitching a wonderful idea that would allow them to drill 12 miles into the earth’s core. According to Business Wire, Quaise Energy has proposed using millimeter-wave beams of light instead of traditional drill bits to get the job done. The plan is to vaporize rock and other molten deposits even without touching them.

Consequently, the startup is in the lab testing stage but hopes to have perfected its technology to drill as deep as one meter by next year, 2023. However, considering the large budget involved, it’s easy to see that this is not a mere experiment. Instead, the aim is to tap into the boundless energy stored beneath the earth’s core.

The energy produced beneath the earth is known as geothermal energy. It is renewable and can be transformed into safe heat and electricity, which will be much better for our ecosystem than solar, wind, and of course, fossil fuels.

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  1. Union University, Available here: https://www.uu.edu/dept/physics/scienceguys/2003Apr.cfm
  2. Insh, Available here: https://insh.world/science/what-if-the-earth-was-hollow/
  3. Research Gate, Available here: https://www.researchgate.net/publication/355763352_Anniversary_of_the_commencement_of_the_sg-3_Kola_superdeep_borehole_drilling_operations