The powerful earthquake that hit Indonesia was just the latest display of violent seismic activity on the archipelago, which stretches across one of the most unstable parts of the Earth's surface. The country's position on the planet's crust means it will continue to experience such catastrophes, just as it has done for the past 50 million years or so, according to seismologists. "The problem with Indonesia is that you have an area of intense seismic activity coinciding with a very densely populated part of the world," said Gary Gibson, professor of seismology at the RMIT University in Melbourne, Australia. "It...