Geophysics from the Zurich Technological Institute (Eth Zurich) have made a groundbreaking discovery, finding mysterious zones in the lower mantle of the Earth where seismic waves behave unusually. This discovery may indicate the presence of materials with different temperatures or compositions than the surrounding areas, challenging traditional ideas about tectonic plates and raising many questions.
Exploring the depths of the Earth directly is currently impossible, as drilling to the mantle layer remains out of reach and measuring pressure or temperature in those conditions is extremely challenging. Therefore, scientists rely on indirect methods such as analyzing seismograms. Similar to how doctors use ultrasound to examine internal organs, geophysicists study seismic wave behavior to create models of the Earth’s internal structure.
Collaborative studies by Eth Zurich and the California Technological Institute have revealed unexpected anomalies – remnants of sunken plates, not in typical subduction zones but under oceans and continents where such processes would not be expected. These discoveries were made possible through the use of Full Wave Inversion (FWI) technology, which required massive computing resources including the Piz Dain supercomputer in Lugano.
One particularly peculiar zone was discovered beneath the western part of the Pacific Ocean, where current theories had not predicted subduction to occur. The exact composition of these anomalous areas remains unknown, with Professor Andreas Fichtner comparing the discovery to finding an “artery in an unexpected place” using a new research tool.
Researchers speculate that these anomalies could be caused by ancient silica rocks dating back 4 billion years ago in the mantle, or regions of accumulated dense rocks. Further exploration and the development of advanced models will be needed to clarify these findings.
This new technique represents a significant step towards a deeper understanding of Earth’s inner workings, although it also highlights the numerous mysteries that still need to be unraveled.