Daily Times

The glacial waters of Lake Palcacocha lap at the 25-foot-tall structure. Billions of gallons of meltwater stretch a mile back to the foot of the ice-capped peaks of Palcaraju and Pucaranra that top out at 20,584 feet.

Scientists and historians believe a huge chunk of glacial ice cap fell into Lake Palcacocha one day in 1941. The instant displacement of millions of gallons of water triggered a massive wave that crashed through a natural barrier. Water, mud, rocks and debris surged into the canyon below and into the streets of Huaraz, the largest city in this part of the Andes and a tourist destination.

The violent rush hit with practically no warning and killed at least 1,800 people.

It could happen again, at any moment. And if it does, the outcome is likely to be much worse.

After years of seemingly inexplicable delays, the regional government has finally begun constructing a new high-tech early warning system to continuously monitor the lake and quickly relay emergency alerts to Huaraz and other downstream communities.

Notably, average temperatures in Peru have increased by about 4 degrees Fahrenheit (2.2 degrees Celsius) since the late 1800s, and the nation’s glaciers have lost as much as 90 percent of their mass. At Lake Palcacocha, melting has added perhaps 4 billion gallons of water to the lake, which is just waiting to breach the dam when the next hunk of hulking ice cap plunges into its depths.