Supercomputer unveils unexpected anomalies lurking in Earth’s lower mantle
Miles beneath the Pacific Ocean, in a region of Earth’s mantle where conventional wisdom says nothing unusual should exist, scientists have discovered something extraordinary. Using innovative technology to analyze seismic waves, researchers have identified massive structures that challenge fundamental theories about how our planet formed and evolved.
For decades, seismologists have studied Earth’s deep interior using seismic waves from earthquakes. By recording these waves at seismic stations worldwide, scientists can create images of structures deep within Earth. The new study, published in Scientific Reports, has uncovered anomalies beneath vast oceans and continental interiors, far from any known plate boundaries.
The research team from ETH Zurich and the California Institute of Technology used a sophisticated technique called full-waveform inversion (FWI), which examines entire seismograms to capture a more complete picture of Earth’s interior. The massive computational requirements of processing this data necessitated the use of the Piz Daint supercomputer, one of the world’s most powerful computing systems.
The most striking finding emerged beneath the western Pacific Ocean, where researchers identified a massive anomaly between 900 and 1,200 kilometers depth. According to current plate tectonic theories, this material couldn’t have come from subducted plates because the region has no recent history of subduction zones.
The discovery suggests these deep Earth structures might have diverse origins, potentially including ancient silica-rich material that has survived since the mantle’s formation about 4 billion years ago, or zones where iron-rich rocks have accumulated over billions of years due to mantle movements.
The study challenges our understanding of Earth’s internal structure and dynamics, suggesting that processes beyond plate tectonics may play significant roles in shaping Earth’s interior. The findings have important implications for how scientists reconstruct past plate movements and understand Earth’s thermal and chemical evolution, opening new avenues for research into mantle composition and dynamics.