Congo-Kinshasa

An underwater avalanche of sand from the Congo River tore through internet cables on the floor of the Atlantic.

The Congo River carries more water than any other river in Africa, and with the water come vast amounts of sand and mud. Beyond the river mouth, the channel continues as a deep canyon under the sea.

In January 2020, shortly after an unusually large flood, the sediment began to move. The avalanche raced down the canyon, picking up speed as it went.

It travelled more than 1,100 kilometres into the deep ocean, the longest flow of its kind ever measured. Along the way it snapped two telecommunications cables on the seabed, and internet slowed across large parts of western, central and southern Africa.