The richter scale measures the intensity of earthquakes on a logarithmic scale. the magnitude of an earthquake on the richter scale can be defined by m=2/3log(e)-3.2, where e is the energy of the quake in joules. the 2011 tohoku earthquake in japan measured 9.1 on the richter scale. the 1999 hector mine earthquake in eastern california had a magnitude of 7.1. calculate the energy released by each earthquake.