A series of damaging earthquakes following a magnitude 8.6 earthquake off the coast of Indonesia in April is prompting U.S. scientists to call for speeding up work on developing an improved and reliable system that can be used for forecasting aftershocks in the days after a powerful earthquake. "No other recorded earthquake has triggered as many large aftershocks around the world. We believe this was because it was the largest 'strike-slip' earthquake (where the two sides of a fault slip horizontally past each other) ever recorded, involving horizontal motions," said Roland Burgmann, a professor in the Department of Earth and Planetary Science at the University of California.