What’s up with the Nepal earthquake?

In the study of giant hurricanes, the Saffir-Simpson scale provides a way to measure the relative magnitude of each storm. However, the scale has been calibrated on the basis of storms that have already occurred, and it’s not beyond nature to unleash a storm in the future that breaks the scale. Similarly, there haven’t been enough earthquakes logged in record books to know how many make a pattern, how much is too strong, or if there are time-bound ways to accurately predict earthquakes.