Scientists at Rice University in Texas and Princeton University in New Jersey have used seismic data from 227 East Asian earthquakes between 2007 and 2011 to image depths some 900km (560 miles) below the ground.
Structures imaged include a high-velocity colossus beneath the Tibetan plateau, and a mantle upwelling beneath the Hangai Dome in Mongolia. The researchers hope to use the imaging to find hidden hydrocarbon resource.
‘With the help of supercomputing, it becomes possible to render crystal-clear images of Earth’s complex interior,’ says principal investigator and lead author, Min Chen, of the study. ‘We are combining different kinds of seismic waves to render a more coherent image of the Earth.’
‘What is really new here is that this is an application of what is sometimes referred to as full waveform inversion in exploration geophysics,’ says study co-author Jeroen Tromp.
The researchers combined seismic records from thousands of stations for each earthquake using supercomputers to produce scientifically accurate, 3D images of the subsurface beneath immense geological formations.
‘In the computer, we set off these earthquakes,’ says Tromp. ‘The waves ripple across southeast Asia. We simulate what the ground motion should look like at these stations. Then we compare that to the actual observations. The differences between our simulations and the observations are used to improve our models of the Earth’s interior.’
‘What’s astonishing is how well those images correlate with what we know about the tectonics, in this case, of East Asia from surface observations,’ he adds.