A Look Inside – The Earth’s Core and Independence Day

So my wife and I had a rare evening without any small children and decided to make the most of it by going to see a movie. We chose to go see Independence Day Resurgence, mostly for nostalgia. We both loved the original movie from the 90’s and was hoping that the movie would live up to its predecessor. Sadly it did not.

Apart from the various reasons at this movie just not being very good is the entire premise of the alien attack on Earth.

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They wanted to drill to the planet’s core to basically refuel their ships. The movie kind of lost me there, but it made me think what how would we actually wanted to drill to the core of our planet. How long would it take? What kind of rocks would we drill through? Has it even been tried before?

Earth’s Core

earth-layers

The Earth’s Core is made up of four distinct layers: the crust, mantle, outer core and inner core. These layers vary in makeup, temperature and density.

The crust is either made up primarily of granite or basalt. Granite on the continental crust and basalt is primarily found in the oceanic crust.

The mantle is primarily made up of olivine-rich rock that traditionally contain magnesium, iron and silicon monoxide.

The core is split between two layers the outer core will contain a liquid iron nickel allow, due to its high temperature. The inner core is in a solid state or iron nickel allow due to the increased pressures.

The Crust

The crust can vary in thickness based upon its location but it is traditionally between 20 to 30 miles thick on the Continental Crust and 3 to 6 miles thick at the Oceanic Crust. This difference in thickness is the reason that most attempts at drilling has been attempted at the Oceanic Crust.

The latest International Ocean Discovery Program ended without success in February of 2016. The had set out to drill 4,265 feet to continue the goal of drilling the three miles required to reach for the first time the beginning of the mantle.

There is currently a 1 Billion dollar effort to drill to the mantle, an effort that has been going on since the 60’s. Currently 12 km by a Russian team is the furthest that anyone has drilled.

Drilling To the Center of the Earth

core

The feat of actually drilling to the center of the earth, the inner core of the planet involves drilling through thousands of kilometers. This involves many barriers that we would have to overcome. Namely intense heat and technological limitations we currently have.

Drilling over water allows for us to reduce he distance required to drill to reach the mantle to around 6 miles. The cutting process involves the usage of very long pipes and a diamond drill bit. These bits are fragile, and traditionally don’t have a very long life. Causing frequent bit changes and a rather prolonged drilling process. In addition the temperature drastically increases the further you drill. approximately 77 degrees Fahrenheit for every 0.6 miles. Meaning that the temperature is already approaching 500 F as you approach the Mantle.

The mantle is thousands of kilometers in thickness and it’s molten rock can have temperatures in thousands.

The core itself includes a liquid outer core and a solid inner core. The distance between the two is again thousands of kilometers and the temperatures could be 10,000 F.

The drill bits also can only take so much heat, the Kola Superdeep Borehole had to stop at 12,262 meters after 19 years of drilling due to worries of intense heat.

Independence Day Drilling

So keeping all of this in mind, we are to believe that the drilling from the aliens in Independence day would only take a few hours. They of course aren’t restricted by usage of a diamond drill bit, and intense temperature and pressure restrictions. They utilize a high beam laser drill.

We are approaching that potential technology, as the Advanced Research Projects Agency had started back in 2012 to utilize laser drilling through special optical fibers. They have been able to drill through sedimentary rock. Though what is still restricting is laser power requirements, that ultimately restrict drilling with this method currently at just a few km below the surface.

Though perhaps as technology and power creation methods improve we will be able to use this method to drill to the core of the earth. Until then we will have to be satisfied with the aliens in Independence Day doing that for us.

What does everyone think? Is the current methods of utilizing diamond drill bits ever going to be successful at getting to the Mantle? Or should we focus on lasers as our method for drilling and invest more into increasing its power capabilities to reach greater depths?