Where was the 2015 Nepalian Earthquake located? what caused it?

Measuring 7.9 on the Richter Scale, The epicentre was situated 80km north-west from its Capital, Kathmadu. This happened from the Eurasian Plate colliding with the Indo-Australia Plate. The focus was only 15km deep making it more violent. This Earthquake also mange to disrupt Tibet, India and Pakistan.