Moving hotspot formed Earth's longest straight underwater mountain chain
Spanning 5,000 kilometers along the Indian Ocean's 90-degree east longitude, the ridge rivals the length of North America's Rocky Mountains. This discovery sheds new light on the movement of Earth's tectonic plates and their intricate dynamics.
Dr. Hugo Olierook, a co-author of the study and a researcher at Curtin's School of Earth and Planetary Sciences, explained that high-precision dating of minerals from the ridge reveals it formed between 83 and 43 million years ago as a vast volcanic chain. The oldest sections are located in the north, near present-day India.
"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 kilometres within the mantle over time," Dr. Olierook said.
"This type of hotspot movement, while believed to be common, is difficult to substantiate and has previously been documented only in a few Pacific Ocean hotspots. This marks the first recorded case in the Indian Ocean."
The findings revise the ridge's estimated age and origin while enhancing scientists' ability to model Earth's tectonic plate movements over millions of years.
Professor Fred Jourdan, another co-author from Curtin's School of Earth and Planetary Sciences and the John de Laeter Centre, emphasized the importance of precise dating techniques in reconstructing 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 applying high-precision dating, we can refine these models significantly, offering better insights into the movements of ancient continents."
Lead author Associate Professor Qiang Jiang, now at the China University of Petroleum, stated that understanding the Earth's internal processes is key to 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.
Research Report:Formation of Earth's longest preserved linear volcanic ridge: implications for hotspot motions and lateral plume flows
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