Why is it so hard to predict when an earthquake will happen and its strength?

The death toll from a powerful 7.7-magnitude earthquake in Myanmar jumped to more than 1,000 on Saturday as more bodies were pulled from the rubble of scores of buildings that collapsed when it struck near the country’s second-largest city.

Professor Gyorgy Hetenyi, from the Institute of Earth Sciences at the University of Lausanne, explains the geology of the earthquake-affected area and suggests ways people can prepare for earthquakes, such as introducing earthquake science courses in schools, even in highly politically and socially unstable countries.