Why is there a "black chimney" at the bottom of the sea

In 1977, when American geologists took the Alvin submersible to investigate the seabed of the eastern Pacific ridge, they were surprised to find that there stood some "chimneys" erupting "thick smoke" outward. The seabed is not a factory. How can there be a chimney? Is it a base established by aliens? What is more puzzling is that there are many strange creatures growing next to these chimneys with thick "black smoke", as if it were a magical world.

This strange phenomenon has attracted many visits from scientists, and the veil of this mysterious underwater world has been gradually lifted. It turns out that what comes out of the "black chimney" is not smoke, but hot black hydrothermal fluid! Scientists call it submarine hydrothermal. These "black chimneys" are formed by submarine hydrothermal eruption. If you want to touch it directly with your hand, you must not, because the temperature at the outlet of these "black smoke" is as high as 300 ~ 400 ℃, which can easily scald your hand. Even if you drive a submersible close to it, you must be careful, otherwise there will be an accident of machine destruction and human death. In addition to the high temperature, these "black smoke" usually have strong acidity. The pH value of some "black smoke" is close to that of the aged vinegar we usually eat, which can reach about 2.8.

So why is deep-sea hydrothermal black? In addition to the high temperature, it also contains a large number of toxic gases, such as hydrogen sulfide, methane, hydrogen, and metal ions such as iron, copper, lead and zinc. For most creatures on land, this is a place of death. The toxic substances in the "black smoke" are enough to kill them immediately! According to common sense, no life can survive in such a bad environment. This should be a barren land. However, the situation on the seabed near the "black chimney" is just the opposite. This is simply the "oasis" of life. In a small area of 1 square meter, the number of clams and other animals can even exceed 300, which can be described as "dense"! It is also a paradise for all kinds of microorganisms, breeding many microorganisms that live by "eating" and "black smoke".