Recent research from Curtin University has unveiled groundbreaking insights about the Ninetyeast Ridge — the longest straight underwater mountain chain on Earth. Stretching a remarkable 5000 kilometers along the Indian Ocean’s 90-degree east longitude, it closely rivals the length of North America’s iconic Rocky Mountains, providing an essential understanding of tectonic plate movements.
Co-author Dr. Hugo Olierook from Curtin’s School of Earth and Planetary Sciences emphasizes that high-precision dating of minerals sourced from the ridge indicates its formation occurred between 83 and 43 million years ago as a colossal volcanic chain, with the oldest segments located in the northern region, near India.
This discovery challenges previous assumptions and significantly enhances our knowledge of geological processes.
“Unlike most volcanic hotspots that remain stationary in the mantle and create volcanic trails as tectonic plates drift over them, this study found that the hotspot responsible for the Ninetyeast Ridge moved by several hundred kilometers within the mantle over time,” Dr. Olierook said.
“This kind of hotspot movement is thought to be common but is hard to prove and has only previously been demonstrated for a few hotspots in the Pacific Ocean, making this the first documented case in the Indian Ocean.”
This discovery not only redefines the estimated age and origin of the ridge but also enhances scientists’ ability to create highly accurate models of Earth’s tectonic plate movements over millions of years. Co-author Professor Fred Jourdan from Curtin’s School of Earth and Planetary Sciences and the John de Laeter Centre emphasized the importance of precise dating techniques for unlocking the mysteries of Earth’s geological history.
“For years, rough age estimates of the Ninetyeast Ridge have been used to construct models of how Earth’s tectonic plates moved and reconfigured,” Professor Jourdan said. “By using high-precision dating, we can refine these models significantly, leading to better insights into ancient continental movements.”
Lead author Associate Professor Qiang Jiang highlighted the critical need for precise knowledge of Earth’s internal structure. This understanding is essential for accurately predicting natural disasters like earthquakes and volcanic eruptions.
“Currently, this is far from being the case, so studies like this one are a major step in the right direction,” Associate Professor Jiang said.
Journal reference:
- Qiang Jiang, Hugo K. H. Olierook, Fred Jourdan, Diana Carmona Hoyos, Renaud E. Merle, Evelyn M. Mervine & William W. Sager. Earth’s longest preserved linear volcanic ridge generated by a moving Kerguelen hotspot. Nature Communications, 2024; DOI: 10.1038/s41467-024-54092-6