Landslides are usually easy to predict, but sometimes the array of weather and geological conditions creates a dangerous flow of debris with unbelievable consequences. In the past, when mankind did not have the tools to predict a landslide, the consequences were deadly and land altering. The twentieth century was full of landslides, so let’s take a look at some of them.
The Usoi Dam is the tallest dam in the world; towering at 1860 ft. Tajikistan doesn’t have to thank its engineers for creating the dam though, it is created by Mother Nature. In 1911 a strong earthquake triggered a massive landslide that dammed Murgab River and created Lake Sarez. Similarly a Diexi earthquake in 1933 created a huge dam on Min River and killed more than 550 people in the nearby village of Diexi. Soon after the dam broke down, caused a flood and killed another 2500 people.
Italy is especially prone to landslides, in 1954 in Salerno rain was falling for 16 hours and 300 people died in the debris of a landslide. In 1963 city of Longarone was affected by a landslide that caused the overtopping of Vajont Dam, one of the tallest dams in the world, and caused thousands of casualties. The accident is still considered one of the five greatest failures of engineers and geologist, because they disregarded all warning signs and negative appraisals during the construction. The governmental owned company went ahead and built the dam even though the conditions were less than ideal.
Japan and Peru also have their fair share of landslides. After the 1970 Ancash earthquake a mass of stones, rocks, mud and ice hit the Peruvian city of Yungay and buried it deeply in the debris. More than 50 million cubic meters traveled by speed almost 300 km/h and hit the town instantly. Only 92 people out of 25 000 survived. Another landslide in 1968 in Japan even swept two buses out of the road and killed 104 people.