Chinese scientists have conducted a detailed "chemical element checkup" of the mud and sand at the bottom of China's eastern waters, providing precise data to support spatial planning, ecological environment protection, and resource exploration in the region. The results were published recently by the China Geological Survey.

China's eastern waters are a key region connecting the Eurasian continent and the Pacific Ocean, including the Bohai Sea, Yellow Sea, and East China Sea. Drawing on nearly two decades of marine geological survey efforts, the research team has built the most extensive, complete, and reliable geochemical dataset ever recorded for the region.

Scientists integrated field measurement data from over 10,000 stations and introduced machine learning technology to address the issue of simulation accuracy in areas with data gaps. This approach enabled them to map the locations, concentrations, and distribution patterns of dozens of chemical elements, such as iron, manganese, copper, and rare earth elements.

Dou Yanguang, a researcher at the China Geological Survey's Qingdao Institute of Marine Geology, said the results would serve as a "navigation chart" for the development and protection of China's eastern waters.

"With this element distribution map, we can quickly identify polluted areas and ecologically sensitive zones, draw marine ecological protection red lines, better control marine pollution and risks, and pinpoint seabed mineral resources to reduce blind exploration," Dou said.

He also pointed to their crucial role in helping scientists understand the ocean's history and decode the evolutionary history of the Earth, as the layers of mud and biological remains deposited on the seabed are like a "thick marine diary", recording millions of years of continental drift, climate change, and river shifts.

By comparing sediment characteristics from rivers such as the Yellow River, the Yangtze River, and coastal rivers in the provinces of Zhejiang and Fujian, as well as Taiwan, the research team found that moving southward, the warmer and wetter climate causes rocks and minerals to break down more completely through chemical reactions.

They also found that the distribution of sediment elements is influenced by factors such as seabed grain size, the scouring effect of ocean currents, and localized hydrothermal activities near tectonic plate boundaries or volcanic zones.

The China Geological Survey stressed the importance of this work in filling a long-standing gap in systematic geochemical mapping of seabed sediments in China's eastern waters, and contributing to building a maritime power.