"Congee boiling in a pot." Certainly not imminent (more like a slow simmer) and maybe ultimately won't even pan out, but this story seems about par for the course in 2020.
Andrew Singer
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Originally published on Inkstne.com by Stephen Chen.
Unusual volcanic activity suggests there are two huge magma chambers under Wei Mountain in northeastern China, researchers say. It has not erupted for more than 500,000 years, but the surprise findings show the area is still active.
A volcano in northeast China could be “recharging” for an eruption, with a vast amount of magma believed to be rising up underneath it, according to a team of geophysicists.
The researchers say they discovered two huge magma chambers under Wei Mountain in Heilongjiang, near the border with Russia and North Korea. Their modeling suggests the chambers dwarf the volcano, which is 328 feet tall and 3 miles wide.
The researchers say they discovered two huge magma chambers under Wei Mountain in Heilongjiang, near the border with Russia and North Korea. Their modeling suggests the chambers dwarf the volcano, which is 328 feet tall and 3 miles wide.
It was a surprise discovery, since the volcano last erupted more than 500,000 years ago and was considered extinct. Geologists have been more focused on Changbai Mountain (known in North Korea as Mount Paektu), to the south, whose eruption in 946AD was one of the most powerful volcanic events ever recorded, its fallout zone spanning from Japan to Greenland.
But the volcanic fields of Changbai and Wei “would be linked to some degree,” according to the peer-reviewed study, published in the journal Geology this month.
Geophysicist Zhang Haijiang and a team from the University of Science and Technology of China visited nearly 100 sites across Wei Mountain for the study.
They used sensors to detect abnormalities deep underground. They were looking for magma – which usually has a lower conductivity than hard rock – and they found it: an unusual blip from 9 miles underground, followed by another one at 5 miles.
Their computer modeling suggested there could be two giant magma chambers with a combined depth of more than 6 miles. Those chambers were part of a bigger system that could be “linked with the Changbai volcano by secondary mantle convection,” Zhang wrote, referring to the process that causes tectonic plates to shift.
According to their calculations, 15% of the upper of the two chambers was now filled with molten rock. Some studies have suggested that a volcanic eruption could take place when a chamber fills to 40% magma.
Wei Mountain is part of the Wudalianchi volcanic field, which previous studies have also found could be connected to Changbai – whose most recent eruption was in 1903.
Zhang and the team noted that seismic activity had increased at Changbai from 2002 to 2005 and concluded that “volcanic activity in northeast China is likely to be in an active stage.”
Xu Jiandong, director of the volcanic research division at the China Earthquake Administration in Beijing, said the last eruption at the Wudalianchi field was in the early 18th century, forming two volcanic mountains: Laohei and Huoshao.
"After decades of monitoring on the site, we’ve picked up almost nothing. The whole area has been very, very quiet." - Xu Jiandong, China Earthquake Administration
He said seismic stations had been monitoring the two young volcanoes for several decades and had not detected any sign of active magma chambers under them, meaning the findings of the Wei Mountain study were mysterious.
“If there really are huge magma chambers in the area, we should have detected some related seismic activities,” he said. “But so far, after decades of monitoring on the site, we’ve picked up almost nothing. The whole area has been very, very quiet.”
The Wei study would need to be verified by long-term seismic data that would be collected by new stations at Wei Mountain, Xu said.
“What we know for certain is that the Wudalianchi region is active – it’s like congee boiling in a pot,” he said.
Numerous studies in recent years have suggested a low risk of an immediate eruption in the area. For that reason, the government had not set up monitoring stations there, said Xu, adding that “we are not prepared for an eruption.”
Stehen Chen