Oscillations started by the Sumatra-Andaman tsunami quakes last December are providing vital information about the composition of the Earth as well as the size and duration of the tremors, scientists have said. A team of international scientists led by Jeffrey J Park of the US has said that the Sumatra-Andaman earthquake produced the best documentation of Earth's free oscillations ever recorded, according to a press release posted in science portal EurekAlert. "This earthquake may resolve several controversies, such as whether a heavy slagheap of old tectonic plates is stuck near the core-mantle boundary beneath Africa, or even whether microscopic crystals...