Where on Earth the Largest Landslides Threaten: New Findings from Ostrava Scientists

Scientists from the University of Ostrava have taken a fresh look at some of the most destructive natural disasters on our planet—so-called megalandslides. Their research shows that these giant landslides are not mainly predisposed by steep slopes, rock types, or climate, as was often thought. Instead, the major factor is the topographic setting, which reflects the geological evolution of the landscape. The most at-risk places are mountain ranges along major fault lines and volcanic regions.

Landslides can come in many sizes. Some move only as much rock as would fit in a few rooms, while the largest events set entire mountains in motion. To measure them, scientists use volume. One cubic meter—the size of a household fridge—is the basic unit. Megalandslides start at more than one cubic kilometer, which equals a billion “fridges.” Fewer than 500 such events have ever been recorded on continents. The last one happened in 2008 during the devastating earthquake in China′s Sichuan Province.

These rare but devastating events were the focus of research by Professor Tomáš Pánek and Dr. Michal Břežný from the University of Ostrava, working with Professor Oliver Korup from the University of Potsdam.

“Even the smallest megalandslide would mean that a medium-sized European town would be completely buried by debri. That shows how tragic such an event could be in any densely populated area. What′s surprising is that no one has ever systematically mapped these giant landslides on land. We actually know more about them on the ocean floor—or even on other planets—than on Earth′s continents,” says Professor Pánek.

The team′s study, published in Communications Earth & Environment (part of the Nature group), reveals that nearly two-thirds of all recorded megalandslides are found in volcanic or sedimentary rocks, and most occur within 50 kilometers of major geological faults. The researchers reached these conclusions using a modern statistical method called Bayesian regression, which allowed them to weigh the role of different factors.

The project was supported through the Jan Amos Komenský Operational Programme.

Updated: 16. 09. 2025