The Sleeping Giant / Sid Perkins

The growing activity of a volcano that lies beneath a calm-looking lake prompts Chinese and Korean scientists to work in a rare collaboration

The serenity of the waters of the "Heaven Pool", one of the most popular tourist destinations in Northeast Asia, hides the fact that the pool lies at the mouth of one of the most dangerous volcanoes in the region - a peak known as Mount Changbai by the Chinese, or Mount Pictu by the Koreans. This 2,744-meter-high volcano, which stands on the China-North Korea border, last erupted in 1903, but in recent years it has shown signs of resurgence.

Three Asian rivers originate from the pool and when erupting they may send down a destructive mixture of hot ash, mud and water, with the texture of wet concrete, known as lahar. A major eruption would send streams of such material down the mountain that would threaten the lives of hundreds of thousands of people.

The great earthquake that struck Japan in March 2011 and the tsunami that followed, roused the scientists in the volcano area to action. In August 2011, in an unusual collaboration, scientists from China, North Korea and South Korea conducted field research on the summit, and in the fall they held a workshop on natural disaster prediction and preparation. The researchers connected to a seismic network installed on the Chinese side of the mountain in 1999 and made measurements using GPS equipment on its slopes. They detected a series of small earthquakes, as well as a gradual elevation of the summit since 2002 - which they attribute to the movement of magma into an underground pocket under the mountain. The scientists believe that the trend is coming from deep in the Earth's mantle, which increases the likelihood of an eruption.

Despite the international cooperation, the sharing of data so far has been little. This is what Sung-Hyo Yoon from Pusan ​​National University in South Korea tells us, and says: "Until now, the work has not been easy."