Do you know “Journey to the Center of the Earth” by Jules Verne? As expected, the science fiction book set our imaginations ablaze. However, have you ever pondered exactly what it is that lies at Earth’s core? A team of Russian scientists has spent decades trying to reach the Earth’s core by drilling into an isolated peninsula. However, the team finally made a discovery after many years of labor that prevented any further exploration.
A Look To The Earth’s Core Reveals Scientific Mysteries
The Search
The United States and the Soviet Union initially competed with one another in an effort to become the first to reach the center of the earth. While the race between the two countries to dominate space is well-known, the race to penetrate as deeply as possible into the Earth’s crust has received much less attention. Even though dirt and rocks may not seem all that interesting in comparison to the vastness of space, they are actually the gateway to the mantle, the planet’s mysterious inner layer that accounts for 40% of its mass. In other words, what could that 40% be made of?
The Search
Project Mohole
In 1957, the United States team began Project Mohole, putting them ahead of their competition. The goal of this project was to collect a piece of the Earth’s mantle by drilling into the seafloor in a region off Guadalupe Island in Mexico. The engineering crew went deep enough to penetrate the ocean floor in the Pacific. The National Science Foundation underwrote Project Mohole. The US House of Representatives eventually pulled the plug on the project after eight years. The Americans were the ones to initiate play, but they were never able to claim the role of leader.
Project Mohole
Located In Kola
For some reason, the USSR team was slow to get going on their endeavor. Actually, the Russians didn’t begin drilling for the planet’s core until May 24, 1970. Pechengsky District is a sparsely populated region in Russia’s Kola Peninsula where exploration drilling has begun. The Russian team’s objective was straightforward: to penetrate the Earth’s crust as deeply as possible. Naturally, they wanted to beat the U.S. team’s 600-foot height. Indeed, a height of 49,000 feet was set as the minimum target.
Located In Kola
Uralmash-4E
For their project, the Russian team needed specialized tools. The Uralmash-4E, a serial drilling rig used for oil wells, did the drilling. For this rig to be able to drill to a depth of 7 kilometers, some adjustments had to be made. The Soviet team invested heavily in the development of instruments to take direct physical measurements at the borehole’s bottom. This meant that the reliability of their measurements was improved. The Uralmash-15000 was added to the squad’s arsenal in 1974.
Uralmash 4E
Bertha Rogers Hole
Meanwhile, the Americans have been making some headway of their own. Lone Star Producing Company began oil exploration in Washita County, Oklahoma in 1974. However, despite their failure to locate oil, they succeeded in creating the deepest hole on the planet at the time. The hole they drilled, now known as the “Bertha Rogers hole,” went more than 31,400 feet below ground. Even though it’s no longer the deepest hole ever dug by humans, it’s still the deepest in the United States.
Bertha Rogers Hole
Closer To The Goal
One of the Russian team’s boreholes went deeper than the Bertha Rogers hole on June 6, 1979. The SG-3 was chosen as the name for the borehole. By 1983, the SG-3 borehole had gone down to a depth of nearly 30,000 feet. The diameter of the opening was 9 inches. As a result, the Russian team was only 10,000 feet away from their target minimum. They put the drills on hold for a year so that various scientists could come and inspect the site.
Closer To The Goal
Started Again
A year later, when the Russian team resumed drilling, they encountered an unforeseen technical issue that caused them to stop working in borehole SG-3. The Russian team was unfazed and decided to drill another borehole. The depth of this borehole was over 7,000 meters (nearly 23,000 feet). The Russian group’s new borehole finally succeeded in 1989. A total depth of 40,230 feet was reached by the drill bit. That’s a good 7.5 miles below the surface of the Earth. This boosted morale and gave the group hope that they would indeed reach 44,000 feet in 1990.
Started Again
A Sudden Change
However, the outcome was not what the Russians had hoped for. They continued to dig deeper, unaware that they were about to run into an unexpected obstacle. A dramatic shift took place as their drill approached the Earth’s core. One of the first indicators of a shift was a gradual cooling of the borehole’s interior. There was a rapid increase in temperature as they dug deeper. As they got closer to their goal altitude of 49,000 feet, the temperature in the hole soared to between 180 °C (356 °F) and a full 80 °C (176 °F). This much heat was unexpected by the crew.
A Sudden Change
A Different Kind Of Rock
As the Russian team descended further into the borehole, they discovered more peculiar phenomena, such as unusually high temperatures. The rocks at those depths were found to have a lower density than expected by the researchers. Consequently, the rocks reacted in various ways to the elevated temperatures. The rocks, for example, felt very much like plastic. In time, this unusual texture became a problem as it made drilling through the rocks extremely difficult. In addition, the heat and the rocks were too much for their machine to handle.
A Different Kind Of Rock
End Of The Project
As they continued to drill deeper into the Earth, the Russian team began to anticipate its completion. Neither the high temperature nor the plastic-like rocks would allow their equipment to last for very long. They worked on it until 1992, but they couldn’t make any further progress. Because of this, they were forced to halt drilling operations. In 2005, the drill site and the Kola superdeep borehole were officially closed. However, just because work stopped on the project doesn’t mean it was useless.
End Of The Project
Kola Superdeep Borehole
Before capping off the borehole, which they named the Kola Superdeep Borehole, the research team uncovered some fascinating results. The data collected from the Kola Superdeep Borehole is invaluable to the study of geology. The Russian team may not have made it to the mantle, but they did succeed in digging the deepest hole ever. Plus, the data they uncovered was extremely useful to scientists generally.
Kola Superdeep Borehole
Fossils Were Found
Tiny fossils of single-celled marine organisms were discovered by the research team at a depth of four miles, indicating the presence of biological activity within the rocks. Being so far below ground level was a surprising discovery. Due to their long preservation at great depths (miles) below the earth’s surface, the fossils were in excellent condition. In fact, scientists determined that the fossils were older than 2 billion years. All in all, this was seen as a success by scientists.
Fossils Were Found
Earth’s Temperature
The data from the Kola Superdeep Borehole allowed for an improved temperature map of the Earth’s interior. This provides geologists with more reliable information about the average temperature of the Earth. During the drill, participants were surprised to find temperatures significantly higher than forecast. This profound shift in Geology demonstrates how much further our understanding can advance with time. In a word, the Russian team is to thank for that.
Earth’s Temperature
Conrad Discontinuity
As a result of the Russian project, a wealth of new geological information was gathered, advancing our understanding of our planet. Many geological hypotheses were verified or disproved thanks to the Kola superdeep borehole’s direct view of the crust. According to the “Conrad discontinuity” theory, a change from granite to basalt should occur somewhere between 3 and 6 kilometers below the earth’s surface. The results of the Kola Superdeep Borehole would prove that this is not the case.
Conrad Discontinuity
Granite Only
Seismic wave analysis led to the development of the Conrad discontinuity theory. This is how scientists have conceptualized the Earth’s crust for some time now, with progressively younger layers of rock (basalt beneath the older granite). This, however, was disproved by the Kola Superdeep Borehole. At the very bottom of the borehole, scientists discovered only granite. This indicated that the metamorphic differences in the rock, and not a change to basalt, were responsible for the variations in the seismic waves.
Granite Only
There’s A Flowing Water
A fascinating discovery was made by the Kola Superdeep Borehole when it encountered moving water many miles below the Earth’s surface. Until then, no one had seriously considered the possibility of liquid water existing at such a great depth below the earth’s surface. This proved that the Earth’s crust is not as thick as previously thought. There were channels for liquids to travel through. The researchers hypothesized that the water flowed because the rocks were subjected to the such intense pressure that the hydrogen and oxygen atoms were forced to escape.
There’s A Flowing Water
It Became A Tourist Spot
Interestingly enough, the Soviet Union’s demise coincided with the closing of the Kola Superdeep Borehole. The area has been abandoned and is now classified as a potential threat to the environment. Still, this did not prevent curious onlookers from stopping by to take a look. It’s hard to believe that the deepest hole on Earth is home to a decrepit drill site littered with rusting wood and discarded metal. Even though the Kola Superdeep borehole has been welded shot, it is still a fascinating discovery.
It Became A Tourist Spot
Still Standing Record
Since the Russian team set the standard, no one has been able to surpass it. The depth of the borehole is equivalent to stacking Mount Everest and Mount Fiji. As of now, the Kola Superdeep Borehole is still the deepest hole ever dug by humans. Did the team manage to drill all the way to the center of the planet? Despite its impressiveness, the Kola Superdeep Borehole is relatively shallow when compared to the depth of the Earth. Truth be told, the borehole only reached about a third of the way through the Earth’s crust and 2% of the way to the planet’s center.
Still Standing Record
A Long Journey Ahead
Other countries, such as Germany, Sweden, and Austria, also attempted to drill to the center of the Earth. However, no other endeavors were successful in surpassing the depth of the Kola Superdeep Borehole. Some were more extensive than others because they departed from a straight line, but none of them went beneath the surface. Getting to the center of the planet is still a long way off for humanity. Perhaps one day we will discover some incredible treasures in the mantle. It appears that we will be experiencing some delay.
A Long Journey Ahead