Napali earthquake raised a city and lowered a mountain

The 7.8 earthquake that occurred in Nepal on April 25 was part of a process that’s been happening for the last 55 million years. As the Indian Plate moves further on its trajectory away from Africa (where it used to be part of Gondwana during the Cretaceous period,) it has been slowly crashing into Asia. Much of this collision has lead to the Asian tectonic plate being forced upward as India goes under it, forming features like the Himalaya mountains. Measurements from recent earthquake show that that process isn’t always completely straightforward.

Jumps, and drops, in altitude

Pressure between the two tectonic plates built up enough that there was a slip, where a giant shift in position lead to the two plates moving to accommodate each other. Part of that readjustment lead to the city of Kathmandu to be pushed three feet higher than before. This jump in altitude may explain why damage was so extensive in the city, even though it was miles away from the earthquake’s epicenter. Conversely, Mount Everest, while still the tallest peak in the world, lost altitude, and now stands one inch shorter than before.

This is not expected to be the start of a larger trend, with Everest sinking into the ground. The Himalayas are still on track to grow their average 0.4 inches per year in a more gradual and gentle manner. However, it’s feared that the large readjustment in April’s earthquake didn’t relieve all the pressure between the Indian and Asian plates that had built up. This could mean more dramatic shifts in the form of another earthquake, or something a bit softer via a movement called seismic creep.

Source: Mount Everest Shrank As Nepal Quake Lifted Kathmandu by Becky Oskin, Live Science