Digging straight through the Earth sounds like a grand adventure, but is it even possible? Most of us would find ourselves underwater if we tried. However, recent drilling projects are aiming to uncover mysteries lying beneath our feet.
China is currently working on an ambitious project to dig a 10,000-meter (32,808-foot) hole into the Earth. They’re aiming to reach layers that date back 145 million years, specifically from the Cretaceous Period. This exploration could provide amazing insights into Earth’s history.
The deepest hole drilled so far is the Kola Superdeep Borehole in Russia, reaching a depth of 12,263 meters (40,230 feet). This project was active from the 1970s until the early 1990s. Scientists discovered that the rocks at such depths are wetter than expected. They also found unexpected types of granite, which shed light on the theory of plate tectonics—a theory not fully accepted until around that time.
To give you an idea of how deep these holes are, the Earth’s crust averages about 30 kilometers (19 miles) thick on land, but it can be up to 100 kilometers (62 miles) thick where mountains rise. Oceanic crust is much thinner, about 6 to 7 kilometers (3.7 to 4.3 miles). Drilling through it is tricky due to the ocean’s movement and pressure challenges.
Dr. Doug Wilson, a geophysicist at UC Santa Barbara, explains that as you dig deeper, the pressure increases dramatically. For every 3 meters (10 feet) down, the pressure rises by one atmosphere. At the center of the Earth, the pressure would be overwhelming—over 1.1 trillion hectopascals. To put that into context, normal pressure at sea level is about 1,013 hPa.
Temperature also poses a significant challenge. The Earth’s inner core is around 5,200 degrees Celsius (9,392 degrees Fahrenheit). Cooling the drilling equipment would be almost impossible, especially as you reach the outer core, which is liquid.
If, against all odds, one could reach the Earth’s core, there would be a brief moment of weightlessness before facing the long journey back up to the opposite side.
While the idea of digging through the Earth sparks our imagination, the reality is filled with scientific hurdles. Nonetheless, ongoing projects continue to push our understanding of what lies beneath us, revealing important insights about our planet’s geology and history.
For more on the Kola Superdeep Borehole and its findings, you can check out this resource from EarthDate.
