The Korea Institute of Ocean Science and Technology (KIOST, Kim Woong-seo, President) announced that collaborative Korea-China research has discovered that the earth’s crust in the Yellow sea may have formed earlier than has been understood so far.

  In the Yellow sea, there is a South China Block, consisting of northern China and the northern Korean peninsula, and a Sino-Korea Block, consisting of southern China and the southern Korean peninsula. It has thus far been accepted that a collision of the two blocks developed crusts in the Yellow sea. However, this most recent joint research has discovered something new about the process of this development of crusts in East Asia, to which the Korean peninsula belongs.

  The collaborative research team of Kim Han-joon, a senior researcher at KIOST, Dr. Hao  of the Chinese Academy of Sciences, and Kim Gwang-hee, a professor at Pusan National University studied the structure of crusts spreading across the jurisdictional sea areas of both countries after authorization from the governments of China and Korea in 2016. The research team set up seabed seismometers along the sidelines of the Gunsan Basin (Figure 1b), and analyzed the results of deep seismic sounding. It found that the upper crust of the Gunsan Basin, unlike the Korean peninsula, is thin while the lower crust is thick. This suggests that the Gunsan Basin formed when the supercontinents* formed - much earlier than has previously been understood, i.e. the collision of the South China and Sino-Korea blocks. This finding is likely to be a critical clue to understanding how crusts in southern China are connected to crusts in the Yellow sea near the Korean peninsula.
 * A supercontinent was an assembly of most or all of Earth’s continental blocks into a single large landmass before being broken up and shifting into today’s continental blocks. Pangaea and Rodinia are examples of major supercontinents.

  Senior researcher Kim Han-joon said, “As the Yellow sea is shared by Korea and China, the cooperation of both countries is essential for research. Such research is meaningful in that it is the first joint endeavor between the two countries in marine geoscience and going forward, I hope it will provide great momentum to additional cooperation in science and technology between China and Korea.”

  This research was conducted under a seismic technology development project supported by the Korea Meteorological Administration and a research project supported by the National Natural Science Foundation of China. Research results were posted on the online edition of the Journal of Asian Earth Sciences, an international academic journal in geoscience, in June 2019.