Nevados Huascaran Avalanche – 1970

The great Peruvian earthquake in May 1970 took place off the north coast of Peru. It measured an impressive 7.9 on the Richter scale and was the deadliest seismic disaster in Latin American history. The quake had a catastrophic impact on the Ancash and La Libertad regions with serious damage caused over an area of some 35,000 sq km (13,500 sq mi).

The coastal city of Chimbote was hard hit, countless other towns and villages were devastated and virtually everything in the Andean valley of Callejon de Huaylas was obliterated. There was massive infrastructure damage and 3,000,000 people were affected.

The most severe single consequence was the world’s worst-ever snow-and-rock slide – the Nevados Huascaran avalanche. The quake destabilized a section of Mount Huascaran 1.5 km (1 mi) long by 900 m (3,000 ft) wide and 900 m (3,000 ft) deep.

This huge mass of rock and glacial ice detached and thundered down the mountain, reaching a speed of 160 kph (100 mph) and destroying everything as it gathered momentum.

The provincial capital of Yungay was in its path and didn’t stand a chance. Neither did the smaller town of Ranrahirea. Both were obliterated and buried 50 m (165 ft) beneath debris left by the avalanche. Just 400 of Yungay’s population of 18,500 survived, wlule in Ranrahirea nearly 2,000 were killed.

It was two days before the scale of the disaster became apparent to outsiders, leaving survivors to claw at heaped rubble with bare hands.

When rescuers finally arrived with heavy equipment and medical supplies, it was too late for those who had been buried alive and for many survivors, who had already succumbed to injuries. The Peruvian government has classified the site of Yungay as a mass grave where all excavation is forbidden.

When: May 31 1970

Where: Mount Huascaran, Yungay Province, Peru

Death toll: Estimated at 20,000 (from a total of up to 80,000 killed by the earthquake as a whole)

You should know: The only foreign victims of the avalanche were Czechoslovakian climbers whose mountaineering team was in the wrong place at the wrong time. Their bodies were never found.