Mount Paektu — a sacred but potentially hazardous volcano straddling the border between China and the Korean Peninsula — has North Korea worried. So worried, in fact, that the country’s insular regime recently allowed its scientists to participate in a rare collaboration with their Western counterparts, resulting in a study that has now been published in the journal Science Advances.

“It is a volcano with a dramatic past, showed some recent activity, and we do not know much about it,” co-author James Hammond from the University of London, reportedly said. “This volcano is quiet at the moment, but it’s definitely got potential. We need to keep an eye on it.”

Mount Paektu, known as Changbai in China, has a violent history. Around 946 AD, the volcano erupted, spewing superheated clouds of gas and ash as far away as Japan. The explosion was one of the most powerful volcanic eruptions in recorded history.

“There's no real consensus as to why the volcano is there in the first place,” Hammond told Motherboard. “It's not sitting on a plate boundary, which is normally where we find most volcanoes."

Today, over 1.5 million people live within 62 miles of the volcano — considered sacred by many North Koreans who believe it to be the birthplace of the late supreme leader Kim Jong-il. Between 2002 and 2005, the region witnessed thousands of tiny earthquakes, triggering fears of another massive eruption.

As a result, in 2011, scientists from North Korea, the U.S., the U.K. and China began an unprecedented collaborative research to reassess what they knew about the volcano.

“It's the first glimpse of the volcano on the Korean side. It gives us a much better picture of what's going on beneath the volcano,” Hammond reportedly said.

According to the findings of the study, which was based on data collected by an array of six seismometers deployed in a 37 mile-long line east from Paektu’s summit, a significant part of the volcanic crust is at least partially molten, made up of a gooey mixture of rocks, liquid, gas and crystals. While the study confirms that the volcano is quite active, the amount of magma the region has is still not clear. 

"I think the risk of a destructive eruption here is very real," Stephen Grand, a seismologist at the University of Texas at Austin, who was not involved in the study, told National Geographic magazine. “The subsurface structure can help with predicting the future, although not with any definitiveness. One would need to follow how the current situation changes with time going forward."