Nestling in the Andes, the Peruvian city of Huaraz is a prime target for a terrifying prospect that has become increasingly real under global warming – a ‘glacial lake outburst flood’ that threatens to wreak havoc on the 120,000-population tourist destination.
The melting of glaciers such as Peru’s Pastoruri has put cities like Huaraz, located just 35 miles downslope, at significant risk of a “glof”, which occurs when the walls of a mountain valley collapse under the weight of meltwater from the disappearing ice.
The town of Huaraz, to which visitors flock from around the world for climbing, mountain biking, hiking and snowboarding, is particularly vulnerable as melting glaciers feed into the glacial Palcacocha lake, just 12 miles upslope.
Nepal is also highly exposed due to its proximity to the highest and largest meltwater sources in the world in the Himalayas, experts warn.
These inherently unstable structures can collapse quickly, especially in a country like Peru which is prone to earthquakes.
Massive glofs are already starting to occur, in countries such as Iceland and in Chile’s Bernardo O’Higgins National Park – but so far they have occurred in very sparsely populated areas.