Is the water in the Yellow, Red, Black and White Seas really yellow, red, black and white?
There are four seas on earth named after their colors. They are the Yellow Sea, Red Sea, Black Sea and White Sea. So, is their seawater really yellow, red, black and white?
The Yellow Sea is indeed yellow many times. The Yellow Sea is located between the mainland of China and the Korean Peninsula and is the confluence point of China's major rivers. Every year, the Yangtze River, Ancient Yellow River, Huaihe River, Liaohe River and Yalu River, as well as the Han River, Tatong River and Qingchuan River on the Korean Peninsula, carry large amounts of sediment into the Yellow Sea. In particular, the ancient Yellow River flowed into the Yellow Sea from the northern coast of Jiangsu during more than 700 years from 1128 to 1855. It carried an average of about 1.2 billion tons of sediment every year, and at its peak it could reach 1.6 billion tons, making it the world's largest river sediment transport. If this sediment is spread on the seabed in the southern Yellow Sea (an area of about 300,000 square kilometers), it can increase the seabed by 3 millimeters. Because sediment particles have a strong absorption capacity in the blue light band, and the absorption amount is about 6.4 times that of red light, the seawater turns yellow after the blue light is reduced. After 1855, the Yellow River changed into the sea from the Bohai Sea. However, although the sediment originally deposited there was stirred and transported by waves and currents, very thick sediments were still stored on the seabed. When the big waves came, the sediments rose and the seawater turned yellow again.
The Red Sea, located between the Arabian Peninsula in Asia and the African continent, is an important channel connecting the Mediterranean Sea and the Arabian Sea. Its sea water is generally blue-green, and only when a seaweed called Chaetochaete reproduces in large numbers does the sea water turn into a bright and unique reddish-brown color. Therefore, people call it the Red Sea.
The Black Sea is located between southeastern Europe and Asia Minor. It is one of the deepest inland seas in the world (the deepest point is more than 2000 meters). It is called the Black Sea due to its deep and dark water color. The Black Sea is a double-layered sea. Most of the upper water comes from the injection of rivers such as the Danube River, the Don River, and the Dnieper River, and the surface density is relatively low; while the deep water is born out of the basin of the ancient Mediterranean Sea, so it is very salty and dense., making it difficult for the upper and lower water bodies to communicate completely. After death, biological secretions and various animals and plants in the upper seawater will sink deep into the depths to rot and stink, leaving the lower seawater in a state of hypoxia for a long time, causing the bottom seawater to be turbid and dark. In addition, anaerobic organisms living in anoxic environments also release carbon dioxide and hydrogen sulfide, which contributes to the discoloration of seawater.
Obviously, a dark sea is not a black sea. Because the area where the Black Sea is located is prone to storms, there are always strong winds of magnitude 6 or above on the sea for more than 10 days a year. Under the agitation of the strong wind, the lower sea water will roll up more, making the color of the water darker, making it look like the Black Sea truly. Of course, in ordinary days, the sky in the Black Sea is mostly dark gray, and the sea water against this color also looks close to black.
The Barents Sea, which stretches into the Arctic Ocean in the Russian part of Europe, is almost completely surrounded by land. Due to its high latitude, severe cold climate, and endless ice and snow all year round, about 200 days of the year are covered by snow-white ice. The sun shines on the ice and produces strong reflections, causing the sea surface we see to be white. People call it the White Sea.