Discussed are some of the reasons for earthquakes which occur in stable crust away from familiar zones at the ends of tectonic plates. Crust stability and the reactivation of old faults are described using examples from India and Australia. (CW)

Several studies of the validity of the intensive time-series design have revealed a post-intervention increase in the level of achievement data (the "momentum effect"). Reports on the development and use of a technique to study the effect as it is observed in several data sets on the learning of plate tectonics. (Author/JN)