What is the largest hole ever dug in the earth?
In terms of depth below the surface, the Kola Superdeep Borehole SG-3 retains the world record at 12,262 metres (40,230 ft) reached in 1989 and is still the deepest artificial point on Earth.
The deepest hole by far is one on the Kola Peninsula in Russia near Murmansk, referred to as the "Kola well." It was drilled for research purposes beginning in 1970. After five years, the Kola well had reached 7km (about 23,000ft).
Drilling the Kola Superdeep Borehole was, for the most part, purely science-driven. Soviet scientists wanted to learn more about our planet's outermost layer, called the crust, to understand how that crust has formed and how it evolved.
It's the thinnest of three main layers, yet humans have never drilled all the way through it. Then, the mantle makes up a whopping 84% of the planet's volume. At the inner core, you'd have to drill through solid iron. This would be especially difficult because there's near-zero gravity at the core.
The deepest point ever reached by man is 35,858 feet below the surface of the ocean, which happens to be as deep as water gets on earth. To go deeper, you'll have to travel to the bottom of the Challenger Deep, a section of the Mariana Trench under the Pacific Ocean 200 miles southwest of Guam.
In order to be able to dig down to the center of the Earth, my friends and I would have needed to dig our way through 6,378 km of rock, mantle, and iron. Most of this journey would be through temperatures hot enough to melt rock, getting as high as 7,000 Kelvin at the center.
Tunneling through the Earth is obviously a fantasy though, given the thousand of miles of molten rock that lie between us and the other side of the world. The furthest humans have ever gotten is the tip of the Kola Superdeep Borehole in northwestern Russia, which reaches a mere 7.5 miles beneath the ground.
The Mariana Trench is an oceanic trench located in the western Pacific Ocean, about 200 kilometres (124 mi) east of the Mariana Islands; it is the deepest oceanic trench on Earth. It is crescent-shaped and measures about 2,550 km (1,580 mi) in length and 69 km (43 mi) in width.
Scientists found microscopic fossils of single-celled organisms at 4.3 miles (7 kilometers) down. And at nearly the same depth, they discovered water. They also found that the temperature at the bottom of the hole reached a blistering 356°F (180°C).
Is there any chance that drilling deep into the Earth could cause a volcanic eruption? No. Even if engineers were to drill directly into a reservoir of molten magma, a volcanic eruption would be extremely unlikely. For one thing, drill holes are too narrow to transmit the explosive force of a volcanic eruption.
How hot is it at the bottom of the Kola Superdeep Borehole?
While the temperature gradient conformed to predictions down to a depth of about 10,000 feet, temperatures after this point increased at a higher rate until they reached 180 °C (or 356 °F) at the bottom of the hole.
Deep in the centre of the planet is the 'inner core', which we think is made of solid iron and nickel. This is surrounded by the 'outer core', which is also made of iron and nickel, but is molten. Convection currents in the outer core create Earth's magnetic field.
The primary contributors to heat in the core are the decay of radioactive elements, leftover heat from planetary formation, and heat released as the liquid outer core solidifies near its boundary with the inner core.
Solving the problem numerically, Klotz found that an object should fall through Earth in 38 minutes and 11 seconds, instead of the 42 minutes and 12 seconds predicted assuming a uniform planet.
Inner Core The inner core is a hot, dense ball of (mostly) iron. It has a radius of about 1,220 kilometers (758 miles). Temperature in the inner core is about 5,200° Celsius (9,392° Fahrenheit). The pressure is nearly 3.6 million atmosphere (atm).
The average distance to the centre of the Earth is 6,371 km or 3,959 miles. In other words, if you could dig a hole 6,371 km, you'd reach the center of the Earth. At this point you'd be in the Earth's liquid metal core.
No one has ever drilled into the mantle before, but there have been a half dozen serious attempts. Decades ago, the Russians drilled deeper than anyone has ever gone. Their Kola Superdeep Borehole was started in 1970 and still holds the world record for the deepest hole in the ground. But they didn't reach the mantle.