According to the research of Professor Mark van der Meijde, mountains influence the impact of earthquakes. It was already known that the topography of an area has an influence on earthquakes but the major influence on local level is new. The mountains can reduce the power of quakes but also send them to certain places, making them more powerful than expected.
The research started after the earthquake in Kathmandu (Nepal) in 2015. More than 100,000 people were expected to die, but in the end ‘only’ around 1,700 people in Kathmandu and 11,000 throughout Nepal died as a result of the earthquake. A lot of research was done, but so far there was no clear answer as to why there were so few victims.
Van der Meijde developed a model that focuses on the role of mountains in the area. It showed that the two ridges between the earthquake and Kathmandu had a very large influence. "The topography in the area 'captured' the energy and ensured that Kathmandu was located exactly in the area with the lowest energy", says van der Meijde.
Thanks to this research it becomes clear that the effect at a local level can vary a lot. For example, according to van der Meijde, Kathmandu was very lucky: "If the earthquake had occurred twenty kilometres more to the west, the mountains would have focussed the energy to the Kathmandu valley.” Then the death toll would have been higher than expected.
Van der Meijde, chairman of the department of Earth Systems Analysis (faculty ITC), and his colleagues published their research in the scientific journal Sensors. The article titled The Influence of Surface Topography on the Weak Ground Shaking in Kathmandu Valley during the 2015 Gorkha Earthquake, Nepal is open access and can be read here (https://doi.org/10.3390/s20030678).