It is possible to obtain a three-dimensional picture of the interior of an object by recording what happens to signals passed through it from various points on its surface. This technique, referred to as "tomography", has found wide application, particularly in medicine. An international collaboration, under the supervision of geophysicist Professor Heiner Igel of LMU and supported by a grant of 5 million Euros from the EU, is now preparing to use tomographic methods to probe the Earth itself. The aim of the project, dubbed QUEST (for "QUantitative estimation of Earth's seismic sources and STructure"), is to construct a three-dimensional picture of the Earth's interior based on the behaviour of sound waves, such as those associated with earthquakes, that pass through it. These vibrations can be picked up by seismographs and recorded on seismograms. "Tomographic reconstruction requires highly complex calculations that can only be run on supercomputers", says Igel. "Their processors are now so fast that the new techniques are set to revolutionize seismology. We hope that they will give us a much more detailed picture of the Earth's internal structure." Seismic tomography is the only tool available for understanding how the Earth's interior functions, and how it powers the movements of the continental plates which are the underlying causes of earthquakes. "We need a better understanding of the structural features of regions in which earthquakes occur, in order to model likely earthquake scenarios in detail", says Igel. "This might also enable us to come up with realistic predictions of pending volcanic eruptions." Precision measurements should also help to localize untapped mineral resources and monitor their exploitation. The participants in the QUEST project come from more than 30 groups, including industrial firms and academic research teams that have made groundbreaking contributions to the field of seismic tomography.
The kick-off meeting for the p
|Contact: Dr. Heiner Igel|