he research vessel Tansuo-1, carrying China's manned deep-sea submersible Fendouzhe (Striver), arrived in Guangzhou, Guangdong Province on May 10, at the end of the successful Pacific Crossing Expedition under the Global Hadal Exploration Program (GHEP) led by China.
Departing from Sanya, Hainan Province on December 6, 2025, the 156-day expedition across the Pacific and back covered a navigation distance of over 40,000 kilometers, roughly equivalent to one full circumnavigation of the Earth along the equator. The mission brought together 83 scientific researchers from six nations, China, Chile, Germany, Denmark, Canada and Spain, representing seven domestic and nine overseas research institutions.
The expedition carried out systematic in-depth studies on cutting-edge international scientific issues, which focused on investigating hadal biodiversity - zones found in the deepest parts of oceans - and plate subduction mechanisms in the Atacama Trench, the world's longest hadal trenches off the western coast of South America, and the Mussau Trench, a rare example of an initial-stage subduction zone located in western Pacific waters northeast of Papua New Guinea.
During the voyage, the Fendouzhe submersible completed 63 manned dives, 50 of which reached depths exceeding 6,000 meters, where researchers collected abundant biological and geological samples, alongside high-definition underwater imagery and video footage, providing critical firsthand data for frontier deep-sea research, deep-sea resource exploration and marine environmental protection.
One of the landmark scientific achievements of the mission was the discovery of the deepest chemosynthetic ecosystem in the Southern Hemisphere at a depth of approximately 8,000 meters. Unlike most ecosystems on Earth that depend on sunlight, this unique deep-sea biological system sustains life through chemical energy released from the seabed, providing evidence for the "Global Chemosynthetic Life Corridor" hypothesis.
Researchers also recorded a diverse range of hadal species, including various types of snailfish and rich benthic fauna, many of which are potentially new discoveries to the global scientific community. In addition, fault structures associated with historical massive earthquakes were identified, providing valuable on-site evidence for studying the seismic impact on deep-sea geological structures and biological habitats.
Experts said the expedition can promote advances in understanding the limits of deep-sea life survival, deep-sea carbon cycling and deep-earth material cycling. It will also offer vital scientific support for deep-sea resource utilization, research into natural disaster mechanisms and improved understanding of global climate change.
The GHEP, listed as a flagship initiative under the United Nations Decade of Ocean Science for Sustainable Development (2021-2030), aims to form a systematic understanding of the Earth's deepest oceanic realms through cross-border scientific cooperation, advanced deep-diving technologies and interdisciplinary research.
Marking the first-ever China-Chile joint manned deep-sea exploration in the Atacama Trench, the joint expedition has not only realized transnational coordinated deep-sea diving and scientific operations, but also accumulated valuable experience for global deep-sea scientific data sharing, professional talent cultivation and long-term hadal seabed observation.
The successful mission demonstrates China's sophisticated technological capacity in deep-sea scientific exploration, as well as the country's firm commitment to advancing international cooperation in marine science and technology.
Going forward, China will further deepen international cooperation in the field of deep-sea science, focusing on long-term hadal environmental observation, research into organisms in extreme deep-sea environments, geological and ecological coupling mechanisms, and joint training of young scientific researchers, Chinese media reported.
Old Version
