North Korea, the notoriously secretive communist state intent on defying the international community, is not known for its collaborations with the West. However, somewhat on the sly, it has been working with scientists from all over the world, including researchers from Cambridge and University College London.
As it turns out, everyone on the planet has a mutual interest in working out whether Mount Paektu, one of the world’s most dangerous volcanoes, is about to erupt. Using an array of devices that pick up seismic waves travelling through the crust, this international team of geophysicists has detected an anomaly between 5 and 10 kilometers (3 to 6 miles) deep.
“This finding suggests that we may be seeing the top of a significant magma storage region in the shallow crust,” the authors note in their study, published in the journal Science Advances. “A large region of the crust has been modified by magmatism associated with volcanism and that partial melt is likely to be present throughout a significant portion of the crust.”
Some of the team installing seismographs near the volcano. Song et al./Science Advances
Mount Paektu is likely a volcano you’ve never heard of, but volcanologists agree that it’s nothing short of a sleeping dragon. Situated on the Chinese-North Korean border, this angry mountain last erupted in 1903, although it’s more notable for the so-called Millennium Eruption in the year 946.
Back then, it unleashed as much energy as 100 million “Little Boy” atomic bombs, the type infamously used on Hiroshima at the close of the Second World War. At the time, Mount Paektu released around 100 cubic kilometers (24 cubic miles) of lava, ash, and incandescent bombs at supersonic speeds.
Understandably, North Korea is worried about its next big eruption, and it’s called in a few scientists from China, the U.S. and the U.K. to assist in its investigation. By working out the location and the dimensions of the magma source beneath the volcano, scientists will be able to determine how much “fuel” it has for its next fireworks display. In general, the larger a volcano’s magma source, the worse the next eruption is likely to be.
Direct visual imaging of the crust is impossible, but there are ways to get around this. One commonly used technique is to see how the speed of seismic waves change as they travel through the crust. Their travel speeds vary depending on the density of the material they’re travelling through, and they travel a lot slower through partly liquid magma than they do through solid rock.
The seismometer positions around the volcano, placed on both the Chinese and North Korean (DPRK) sides of the border. Song et al./Science Advances
By placing a series of seismometers all around the volcano, the team was able to detect a shallow zone of slow-moving seismic waves, which they conclude must be due to a magma source. It’s around 5 kilometers (3 miles) beneath the surface, and was detected as far away as 20 kilometers (12 miles) from the volcano itself. By any measure, this is an enormous source of magma.
Although detecting the presence of magma underneath a volcano isn’t unusual, it does in this case show that Mount Paektu, when it erupts, has the potential to jettison a significant amount of magma out onto the surrounding landscape and up into the atmosphere.
Worryingly, the next cataclysm could come sooner than you think: A recent study revealed that North Korea’s own nuclear weapons tests may inadvertently cause the Mount Paektu to erupt.