China starts drilling a 6.2-mile-deep borehole into the Earth’s crust

In brief: China has started drilling a hole 10,000 meters (32,808 feet, or just over six miles) into the Earth’s crust to carry out scientific exploration. The borehole, which will be the country’s deepest, is located in the oil-rich Xinjiang region.

China’s Xinhua News Agency reports that the project “represents a landmark in China’s deep Earth exploration, providing an unprecedented opportunity to study areas of the planet deep beneath the surface.”

Bloomberg writes that the narrow shaft will penetrate more than ten continental strata, or layers of rock, and reach beyond the cretaceous system in the Earth’s crust, which contains rock that’s 145 million years old.

Drilling of the deepest-ever hole into the Earth’s crust began in northwest #China‘s #Xinjiang Uygur Autonomous Region on Tuesday with a depth of more than 10,000 meters. #ChinaInspires pic.twitter.com/GxgWzsf26y

– CGTN (@CGTNOfficial) June 1, 2023

According to the report, scientists will use the hole to unearth energy resources and rich minerals while studying the deep composition of the Earth. It will also be utilized to evaluate the risks of environmental disasters, such as earthquakes and volcano eruptions. China National Petroleum Corp., which is spearheading the project, says it will be used to test deep underground drilling technologies, too.

The 2,000-tonne drill has a design depth of 11,100 meters. The drilling is expected to take 457 days.

Firstpost writes that the borehole is being dug in the Tarim Basin, a vast depression drained by the Tarim River. At the center of the basin is the Taklimakan Desert, which spans over 212,000 square miles, making it the largest in China. The borehole is located in the hinterland of this desert. The “harsh ground environment and complicated underground conditions” will ensure the project is a challenging one.

“The construction difficulty of the drilling project can be compared to a big truck driving on two thin steel cables,” said Sun Jinsheng, a scientist at the Chinese Academy of Engineering.

In a speech to the country’s top scientists in 2021, Chinese President Xi Jinping called for greater progress in deep Earth exploration.

While the borehole will be the deepest in China, it won’t hold the world record. That is held by the Russian Kola Superdeep Borehole, which, after 20 years of drilling, reached a depth of 12,262 meters (40,230 feet, or 7.6 miles) in 1989. Work had to be stopped in 1992 when the temperature reached 356F, double what was expected at that depth. The facility was shut down three years later.