Recent geophysical discoveries under the Pacific Ocean have unveiled structures deep within the Earth that challenge current understandings of plate tectonics. A research team from ETH Zurich and the California Institute of Technology utilized high-resolution seismic modeling to identify anomalies in the Earth's interior, as detailed in a study published in Scientific Reports.
These anomalies resemble remnants of subducted tectonic plates, yet they are located in regions where such evidence is not expected, such as beneath vast oceans or within continental interiors. The Earth's mantle, situated between the core and the crust, remains largely unexplored due to its inaccessibility, prompting geophysicists to rely on indirect methods like analyzing seismic waves generated by earthquakes.
Using a technique known as full-waveform inversion, scientists analyzed various types of seismic waves with unprecedented precision, employing the Piz Daint supercomputer in Switzerland. This method revealed areas in the lower mantle where seismic waves traveled unexpectedly, indicating the presence of materials with different compositions or temperatures.
One of the most intriguing findings is located beneath the western Pacific, where current theories suggest there should be no remnants of tectonic plates due to the absence of nearby subduction zones in recent geological history. This discovery raises critical questions about the nature of these anomalies.
Researchers propose several hypotheses: they could represent silica-rich zones that have persisted since the formation of the mantle 4 billion years ago, or accumulations of iron-rich rocks formed by convective movements over eons. Professor Andreas Fichtner, who led the model's development, likens the discovery to a doctor finding an unexpected artery after decades of using ultrasound, stating, 'It’s as if we need to rewrite the internal map of the human body.'
According to Thomas Schouten, the study's lead author, this is merely the beginning of unraveling the mysteries of the Earth's mantle. 'We are just scratching the surface of the mantle's enigma,' he remarked, emphasizing the need for even more advanced models to better understand the material properties that generate these anomalies.
The Earth, much like a Lovecraftian narrative, conceals secrets that defy comprehension. Beneath the vast Pacific Ocean lies not a dormant primordial being, but perhaps a lost chapter in the history of our planet, waiting to be uncovered.