Earth’s Longest Straight Underwater Mountain Chain Might Have Been Formed by a Moving Hotspot

New research has uncovered that the Ninetyeast Ridge, a 5,000-kilometre-long underwater mountain range in the Indian Ocean, was shaped by a moving hotspot rather than a stationary one. The study, published in Nature Communications, analysed mineral samples from the ridge and dated its formation to between 83 and 43 million years ago. This discovery challenges earlier assumptions about its origin and sheds light on how tectonic plates have shifted over millions of years.

Implications for Plate Tectonics and Dating

Findings from Curtin University's School of Earth and Planetary Sciences indicate that the Kerguelen hotspot responsible for the ridge moved several hundred kilometres within the Earth's mantle during its activity. Dr Hugo Olierook, a co-author of the study, told Phys.org that this kind of hotspot movement, while believed to be common, has rarely been proven. He noted that this is the first confirmed instance of such movement in the Indian Ocean.

Precise dating methods employed in the research have revised earlier age estimates for the Ninetyeast Ridge, which have long informed tectonic models. According to Professor Fred Jourdan, also a co-author from Curtin University and the John de Laeter Centre, these updated models offer more accurate reconstructions of the Earth's tectonic history. The study highlights the importance of such refinements for understanding ancient geological events.

Future Insights into Earth's Internal Processes

Lead author Associate Professor Qiang Jiang, now with the China University of Petroleum, stressed the importance of comprehending Earth's internal dynamics to predict natural disasters more effectively. He noted that studies like this enhance understanding of processes such as earthquakes and volcanic activity.

The research provides a pivotal contribution to geological science by documenting the interplay between tectonic shifts and mantle dynamics.