In 1961, scientists attempted to drill down to the Earth’s mantle as part of “Project Mohole.” The project was designed to provide geologists and other scientists with access to Earth’s mantle, which is buried beneath some three to six miles of crust — provided you’re drilling from the ocean. If you’re trying to reach the mantle from land, you’re talking about twenty to thirty miles.
Now, some fifty years after the initial attempt, mankind seems poised to attempt it again. In fact, if things go as planned, drilling could begin as soon as 2020. But the question then becomes one of “why in the world would you want to drill a big ol’ hole?”
In short: it could give insight into how the Earth was formed, as well as valuable insight into the inner workings of seismic activity. After all, it’s the circulation of the mantle that allows the tectonic plates to move in the first place.
It’s not as simple as taking a boat to the middle of the ocean and dropping anchor, though. New technologies are going to have to be invented that can withstand the immense pressure of the ocean, as well as the incredible heat of the inner Earth, which can reach upwards of 300-degrees Celsius. According to University of Southampton professor Damon Teagle, that’s not all that has to be addressed:
We will need to drill a 6.5 km hole into… the ocean floor in roughly 4,000 m of water … [and] a ship that can be dynamically positioned to stay precisely above a drill hole for many months at a time.
Translation: Even if they had the tech for it right now, there is still more to it than simply taking a boat to the middle of the ocean and dropping a drill bit.
This is a project that could wind up costing hundreds of millions of dollars and take years to complete. Still, is it worth it? I’ll leave that to Australian National University professor Neville Exon:
This was the original reason ocean drilling began… This could give us a tremendous insight into how the Earth works because the circulation of the mantle is what drives plate tectonics.