If you're looking for an indication of just how powerful the earthquake that hit Nepal on April 25 truly was, than look no further than this story. According to reports, the 7.8-magnitutde quake, which destroyed buildings and claimed the lives of more 8000 people, was so strong that it actually caused some parts of the Himalaya to drop by as much as three feet (1 meter). In geological terms that is an extraordinary shift in plate tectonics, and would help explain why the devastation has been so far reaching.
Satellite imagery taken by the European Space Agency has confirmed the massive shift along the Indian and Eurasian Plates, the two tectonic forces that created the Himalaya in the first place. Those mountains have continued to grow at a steady pace over the millennia because those two plates are colliding with one another. Seismic instability often occurs along the fault lines where two plates meet. In this case, the original earthquake took place at a point in the Earth that isn't far from Kathmandu. The article describes the plate found under that point snapping like a rubber band under the extreme pressure.
The massive quake even had an impact on Mt. Everest itself, although it wasn't quite so dramatic as the three foot drop seen elsewhere. It is believed that the mountain lost about an inch (2.54 cm) of height following the tremors. That change would obviously be imperceptible to anyone on the mountain, but is still an indication of just how strong the quake was.
It is incredibly scary to think about these tectonic forces at work, and just how much damage they can cause. We only need to look at the images that have come out of Nepal over the past few weeks to get an understanding of just how much damage has been done. Those images show a country completely devastated by this disaster, with so much infrastructure wiped out that it will take years to rebuild everything.
Over time, the Himalaya will rebuild as well. In the case of Everest, it will probably regain the lost inch in about a year or so. The other places that have been hit more heavily will take far longer to recover their lost height. But while the Indian Plate continues to push against he Eurasian one, the mountains will continue to grow. And similar earthquakes to this one will continue to happen.