Ancient submarine shipwreck
In 2017, a scientific expedition ship conducted scientific research on the Black Sea. The scientists above were conducting a scientific research project called “Black Sea Map”. This is already their third year of busy work on the Black Sea. On this day, scientists are remotely controlling two underwater robots for underwater operations. Underwater robots are equipped with high-definition cameras, lights and advanced sonar systems. They use sound waves to understand the conditions of the seabed and draw seabed maps. Everything is going on normally. At this moment, the underwater robot discovered something-there is a 23-meter-long shipwreck on the seabed about 2000 meters below the sea surface!
Through the high-definition camera system of the underwater robot, the investigator found that the shipwreck was just like sinking yesterday. The ship’s mast, rudder and rowing stool, and even the ropes on the ship are well preserved. clear and distinct. However, when they studied the debris of the shipwreck brought back by the underwater robot, they were surprised that the ship was built in the 9th century AD and has a history of more than 1,200 years. This is also considered to be the most complete and oldest sunken ship discovered so far.
Seeing this, some people may be wondering: after a ship sinks to the bottom of the sea, it is often eroded by microorganisms and mollusks in the ocean. Modern steel giant ships will inevitably be destroyed, let alone ancient wooden ships? Generally speaking, it only takes about 100 years for a wooden ship to be completely “eaten” on the seabed. However, why did the ancient ships that sank in the Black Sea escape the fate of erosion?
Time capsule under the Black Sea
if we do have a world map, you can see the Black Sea is a landlocked sea between Asia and Europe, it was like a lake surrounded by land only through the Bosporus and the Mediterranean, etc. Connected. The Black Sea is not only in a special location, but also in a special environment. The sea area below 200 meters in the Black Sea has no oxygen. Instead, it is replaced by the world’s highest concentration of toxic hydrogen sulfide, where only a few microorganisms can survive and are lifeless. It is precisely because there are no animals and microorganisms that the ships sunk in the Black Sea can be preserved.
However, even the deepest Mariana Trench (about 8,100 meters) in the world has fishes, not to mention microbes. Why does the Black Sea have such an unsuitable environment for life?
It turns out that the main water source of the Black Sea comes from rivers. These nutrient-rich freshwaters flow into the Black Sea and then mix with the seawater to form seawater with low density and flow in the upper waters. The nutrients brought by the fresh water nourish the microorganisms in the upper seawater of the Black Sea. The microorganisms provide food for small aquatic animals, and the small aquatic animals provide nutrition for the larger fish, forming a vibrant scene. According to statistics, about 180 species of fish live in the upper waters of the Black Sea.
But in stark contrast to the upper seawater, the Black Sea seawater below 200 meters has a high salt content and is difficult to blend with the upper seawater. To make matters worse, although the upper layer of nutrient-rich seawater allows plankton and algae to multiply and provide rich food for fish and other aquatic animals, these creatures will eventually die, and they will go down after death. Sinking, decay, and decomposition. This process continues to consume oxygen. The more biomass, the more oxygen is consumed, which makes the oxygen content under the fertile upper seawater of the Black Sea continue to drop. When there is no more oxygen, bacteria will use the sulfate in seawater to break down these biological bodies, which will lead to the production of highly toxic hydrogen sulfide.
In addition, about 175 cubic kilometers of salty Mediterranean seawater flows into the Black Sea every year and sinks directly into the Black Sea. This increased the salt content of the sea water in the Black Sea, turning it into an almost sterile time capsule, allowing the sunken ship to be preserved for a long time.
For thousands of years made time capsule
now that we know the Black Sea as a special environment like a time capsule to protect the wreck, but another problem has cropped up that the Black Sea is when and how it formed? At present, this issue is still controversial.
In 1998, American geologists William Ryan and Walter Pittman believed that the Black Sea originated from a natural disaster. They believe that after the ice age, 40 square kilometers of seawater flow from the Mediterranean through the Bosphorus Strait every day, which is equivalent to 200 Niagara Falls. After about 300 days, these seawater flooded a lake and a large surrounding plain, forming a black sea far away from the open sea. According to geologists, this 300-day natural disaster was also recorded in the “Old Testament”, which is the familiar story of Noah’s Ark and the flood.
But some scientists do not agree with this view. The archaeologists of the “Black Sea Map Project” have indeed found other possible answers in their research. Archaeologists have extracted more than 400 submarine core samples from the Black Sea. Using advanced equipment, scientists analyzed the elements such as potassium and magnesium in the core samples, and the content of potassium and magnesium elements provided information on the climate of the Black Sea. Magnesium is present in salt water, so by analyzing the concentration of magnesium in different sediment cores, scientists can determine when the Mediterranean salt water began to flow into the Black Sea and how long it would take to fill the Black Sea.
Scientists’ research results show that the Black Sea was not washed out in a flood that lasted for 300 days, but from 16,000 BC to 10,000 BC. For thousands of years, the Mediterranean sea passed through Boss. Formed by the influx of the Prussian Strait. In 2017, archaeologists also found other evidence. They discovered a Bronze Age settlement in a valley off the coast of Bulgaria, which was submerged by the Black Sea between 3000 BC and 1200 BC. Through the exploration of the seabed, archaeologists found signs of wood, pottery and other objects buried 2.5 meters deep in the seabed, and also detected a port. This shows that the Black Sea was “created” by many natural disasters.
Although the oxygen-free and toxic environment on the bottom of the Black Sea has a good protective effect on ancient shipwrecks and cultural relics that have sunk on the bottom of the sea, and provides us with conditions for understanding history, such an environment also threatens the creatures in the Black Sea. Scientists have found that in the past 60 years, the toxic and oxygen-free zone of the Black Sea has expanded upward by about 50 meters, leaving only about 90 meters of space in the upper layer for creatures in the Black Sea. This may be caused by the discharge of fertilizers and organic waste produced by humans into the Black Sea, which makes the sea water of the Black Sea eutrophication, plankton and algae proliferate, which consumes a lot of oxygen. In addition, the lower the temperature of water, the more gas it dissolves, and the dissolved gas includes oxygen. As the global climate warms and the temperature of sea water rises, the oxygen in the sea water will also decrease.
If mankind never stops discharging hazardous waste into the Black Sea and does not take effective measures to slow climate warming, then the Black Sea may become a toxic sea of death in the future.
Ancient submarine shipwreck