moment magnitude scale: a logarithmic scale of 1 to 10 (a successor to the Richter scale) that enables seismologists to compare the energy released by different earthquakes on the basis of the area of the geological fault that ruptured in the quake
scale: an ordered reference standard
criminal negligence: (law) recklessly acting without reasonable caution and putting another person at risk of injury or death (or failing to do something with the same consequences)