The Gakkel Ridge in the Arctic Ocean, Earth’s slowest-spreading mid-ocean ridge, represents a unique environment for studying mantle dynamics and the formation of oceanic crust under extreme conditions. This remote, ice-covered region poses significant challenges for deep-sea exploration. By examining the complex interplay of active and passive mantle upwelling, researchers can gain new insights into the processes driving global mid-ocean ridge systems. Understanding these dynamics is crucial for refining models of tectonic activity and exploring the Earth’s interior, with broader implications for marine mineral resources, volcanic activity, and seismic hazards.

Chair Professor Jian Lin’s research team from the Department of Ocean Science and Engineering at the Southern University of Science and Technology (SUSTech) has recently collaborated with Professor Jiabiao Li’s team from the Second Institute of Oceanography (SIO) at the Ministry of Natural Resources (MNR), as well as scientists from the South China Sea Institute of Oceanology, Chinese Academy of Sciences, and the Institut de Physique du Globe de Paris (IPGP) in France. Together, they have published a groundbreaking study in which, for the first time, they successfully broke through the ice cover and conducted a high-resolution ocean-bottom seismometer (OBS) experiment in the extreme environment of Gakkel Ridge in the Arctic Ocean. Their research proposes that both active and passive mantle upwelling control the global mid-ocean ridge system.

Their paper, entitled “Highly variable magmatic accretion at the ultraslow-spreading Gakkel Ridge”, has been published in Nature.

The mid-ocean ridge is the longest mountain range on Earth and is the birthplace of oceanic crust and oceanic plates, harboring abundant marine mineral resources. The ice-covered Arctic ocean, where the world’s slowest-spreading Gakkel ridge is located, has long been a noticeable gap in deep-sea exploration. The breakthrough by Jian Lin’s research team and collaborators in this area highlights the significant advancements in China’s ocean science research capabilities.

Ultraslow-spreading ridges on Earth are located in remote areas beneath the Southwest Indian Ocean and the Arctic Ocean. While researchers initially explored the Southwest Indian Ridge and proposed a classic mantle dynamics model, high-resolution OBS experiments under the ice-covered Gakkel Ridge were not previously feasible.

In 2021, Professor Jiabiao Li initiated the Joint Arctic Scientific Mid-Ocean Ridge Insight Expedition (JASMInE), marking the first successful large-scale seismic experiment under the Arctic Ocean’s ice cover. This achievement signifies China’s growing leadership in deep-sea exploration and challenges the traditional notion that OBS experiments could not be conducted in the ice-covered regions of the high-latitude Arctic.

Figure 1. Hypsometry of the Earth. Red lines represent examples of ultraslow spreading ridges, the Southwest Indian Ridge and Gakkel Ridge.

Drawing from these recent findings at the Gakkel Ridge and other global ocean ridges, the research team discovered an extremely rich and highly variable magmatic supply at ultraslow-spreading ridges. They further proposed a new mechanism theory that the global mid-ocean ridge system is controlled by both active and passive mantle upwelling.

This discovery challenges the long-held belief that magmatic supply at ultraslow-spreading ridges is limited. These results not only advance the understanding of the theory of tectonics plate dynamics but also highlight the increasing contributions of Chinese scientists in the field of Earth Sciences.

SIO Research Scientist Tao Zhang is the first author of the paper. Chair Professor Jian Lin and Professor Jason P. Morgan are the co-authors, and Professor Jiabiao Li is the corresponding author. SUSTech is the second affiliated unit of the paper.

This work was supported by the National Natural Science Foundation of China (NSFC), Chinese Arctic and Antarctic Administration, Donghai Laboratory, and the Zhejiang Provincial Natural Science Foundation.

Paper link: https://www.nature.com/articles/s41586-024-07831-0

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