Volcano on Fire

Climb with volcano experts to the summit of Nyiragongo, a highly active volcano in the Democratic Republic of the Congo. Twice in recent memory it has erupted, devastating Goma, a neighboring city of 1 million people. To investigate when it might erupt next, scientists climb into its crater toward a bubbling lava lake to deploy sensors and monitor the volcano’s activity.

Silica is a key component of sand but also of lava. The less there is, the more fluid the lava, and the faster it flows. Nyiragongo has some of the lowest-silica-content-lava on the planet, but there’s another clue to the lava’s speed—and it’s not good news.