It is said that the Bohai Sea used to be a plain with flat terrain and Ma Pingchuan. Before the Bohai Sea was formed, miaodao islands was once a hilly area rising from the plain, with a height of about 200 meters. At that time, the climate was cold, and due to the interaction of strong northwest wind and cold wind and cold current, a large number of loess materials floated on the Bohai ancient land plain. Sandstorms not only filled the gullies in ancient land, but also piled up hills. Today, Miao Island's unique loess landform is still discernible. Now there are many fossils of animals and plants, such as mammoths, hairy rhinoceroses and deer, which are suitable for the cold climate of loess. These fossils show that the Bohai ancient land plain was full of vitality at that time.
When scientists interpreted the satellite images of Bohai Bay, they found that there were obvious rectangular image anomalies in the multi-band color composite satellite images, which were divided into two squares by a middle line. The rectangular image is about 24 kilometers long from north to south and 20 kilometers wide from east to west, with the center in Bohai Bay, about 79 kilometers northwest of Dalian. The vertical edge of the rectangular image is consistent with the meridian, the upper and lower bottom edges are parallel to the latitude, and the latitude and longitude are exactly 14 points. This coincidence is not like a natural phenomenon, but seems to be closely related to human activities, reflecting the natural connection with astronomy and geography. This square layout, which faces south, seems to embody the style of ancient urban architecture in China. Could this be a display of an underwater ancient city pool that sank at the bottom of the sea? For this reason, scientists have collected relevant underwater data, and found from the bathymetric map that three shallow water areas coincide with three longitudinal edges of the image. The average water depth around this area is about 30 meters, and the depth of three shallow water lines is between 10 ~ 20 meters, indicating that the anomaly is a normal topographic display, which is consistent with the interpretation that the image is an ancient city pool.
In addition, scientists also visited relevant units. According to paleogeographic research, there have been many transgressions and regressions in Bohai Bay, and the last transgression was about six or seven thousand years ago. From the analysis of human production capacity at that time, it was impossible to complete such a huge project. So, is this an underwater military project stolen by the Russian or Japanese puppet government? Judging from the technical level at that time, it seems that it is not easy to complete such a large underwater project, and the answer from relevant units is also negative.
How is the underwater image anomaly in Bohai Bay formed? Is it a sign of seabed topography or a phenomenon of seabed geological structure? If so, it is difficult to explain such a regular pattern with natural phenomena, and it is not easy to assert conclusions. However, because the anomaly is located in the western margin of Jiaolu fault, earthquakes are frequent and neotectonic movement is strong in this area, and the possibility that the artificial remains of ancient human activities are submerged by seawater due to crustal subsidence cannot be ruled out.
No matter how to explain it at present, it is necessary to further study the image anomalies in Bohai Sea. If the speculation that this is a relic of human activities is confirmed, it will undoubtedly have important scientific value for studying the formation of Bohai Bay, the evolution of paleogeography and the development of China's social history.