New study claims that surface hazards, e.g. landslides, can cause earthquakes

A new study conducted by the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) argues that landslides can trigger earthquakes if they eventually block lakes. This finding is crucial, as until now, we only knew about the reverse scenario, where earthquakes could cause landslides, trigger surface hazards and initiate hazard cascades.

The main idea of the research originated in 2018 when a landslide near Baige village on the Tibetan Plateau, equivalent in volume to 10,000 Olympic-size swimming pools, blocked a river and created a landslide-dammed lake. Following this incident, the research team observed that more than 60 earthquakes occurred within a week in the area, which was unusual for that region. Therefore, to investigate the reason that the region had that significantly increased number of earthquakes an international team collaborated and conducted statistical analyses and modeling.

They concluded that the earthquakes were triggered by the dammed lake, as the water's weight altered stress and water pressure in the earth, affecting fault pressure and causing earthquakes. The study also noted that the filling and emptying of reservoirs have similarly led to pressure changes resulting in earthquakes.

Particularly, researchers stated in their study that chains of natural surface hazards can eventually cause an earthquake. They believe this study will be revolutionary for earthquake risk management, especially in mountainous regions like Switzerland, where catastrophic landslides and rockslides have occurred in the past. The authors also emphasized that future earthquake risk management should consider bidirectional interactions between earthquakes and surface natural hazards. Additionally, they suggest that in the event of an imminent landslide, evaluating the potential risk posed by a blocked river is recommended. In all, it should be mentioned that the volume of glacial lakes will be increased due to climate change and the risk of earthquakes could also change.