The great Himalayan earthquake of 1255 that devastated Kathmandu, killing Nepalese King Abhaya Malla, ruptured the Earth’s surface, as did a later quake in 1934, reports a study published online this week in Nature Geoscience. Previously, great Himalayan quakes were thought to be largely incapable of breaking the Earth’s surface.
Laurent Bollinger and colleagues detected river deposits in Nepal offset by movements along the main fault bounding the Indian and Asian tectonic plates. Using radiocarbon dating, they show that the offsets were caused by great earthquakes that occurred in 1255 and 1934, indicating that both quakes ruptured the surface. The findings imply that strain that builds up in the Earth’s crust as a result of the ongoing collision between India and Asia is released during great quakes every few hundred years.
In an accompanying News and Views article, Thomas Rockwell writes: “Pinning the details of the rupture down in future work could help to develop a more complete view of the earthquake hazard in one of the most densely populated seismic zones in the world.”