In June 2010, a team of scientists and intrepid explorers stepped onto the shore of the lava lake boiling in the depths of Nyiragongo Crater, in the heart of the Great Lakes region of Africa. The team had dreamed of this: walking on the shores of the world’s largest lava lake. Members of the team had been dazzled since childhood by the images of the 1960 documentary “The Devil’s Blast” by Haroun Tazieff, who was the first to reveal to the public the glowing red breakers crashing at the bottom of Nyiragongo crater. Photographer Olivier Grunewald was within a meter of the lake itself, giving us a unique glimpse of its molten matter.
On the eastern edge of the Democratic Republic of Congo, the perilous Nyiragongo volcano towers 3470m over the city of Goma. The wildly erratic volcano is one of the most active on the planet, famous for the violent 200-metre-wide lava lake cradled in its vast summit crater, constantly emitting deadly gases and huge geysers of liquid rock. In 1977 and 2002, the volcano spewed deadly molten rock towards the million inhabitants of Goma, killing hundreds, forcing evacuations and destroying homes—but these were just small disturbances compared to what Nyiragongo is capable of unleashing. The volcano has an intricate ‘plumbing’ system like roots of a tree snaking deep underground, with vents not just at its summit but all around it, and so the threat to Goma is very immediate, and it has been dubbed ‘the most dangerous city in the world’ by researchers. The question is not if the volcano will erupt, but when. And yet, Nyiragongo is one of the least studied volcanoes in the world, because for the past twenty years, the Democratic Republic of Congo has experienced almost constant warfare. A deeper understanding of Nyiragongo must be gained in order to prevent a catastrophe, but serious research has only begun in the past few years. Until we can predict its activity, the question of when? will haunt scientists and seismologists alike, and will determine the fate of nearly one million people.
Lava lakes are extremely rare because they require active volcanoes with eruptions that produce enough active lava to produce them. Currently, there are only five lava lakes in the world: Erta Ale in Ethiopia, Nyiragongo in the Democratic Republic of Congo, Kilauea in Haiwaii, Mount Erebus in Antarctica and Villarrica in Chile.
Lava lakes are large volumes of molten lava, usually basaltic, contained in a vent, crater, or broad depression. Scientists use the term to describe both lava lakes that are molten and those that are partly or completely solidified. Lava lakes can form in three ways: one or more vents in a crater that erupts enough lava to partially fill the crater; when lava pours into a crater or broad depression and partially fills the crater; and atop a new vent that continuously erupts lava that slowly builds a crater that is higher than the surrounding ground. Although destructive and deadly, they do produce stunning photographs.