Mariana Trench

If you ask who is more frightening, the deep sea or the universe, compared to many people will tend to the former. Although the Earth is in the entire universe, not even a grain of dust, with the current human knowledge, the Earth is unlikely to suffer from the threat of the universe or alien civilizations.

In contrast, the ocean is another sense. According to scientists, life was first born in the ocean, even in the first two biological extinctions, the dominance of the Earth is marine life, but with the development of crustal movement, after the final formation of the continents, the ocean has become a very threatening presence.

The threat of the oceans

We often wonder why human beings can't realize the dream of "reaching the moon in the sky and catching the turtles in the ocean", as in the case of space and aviation, but the progress in exploring the ocean is extremely slow.

Humans can use the existing physical and astronomical knowledge to solve many of the difficulties faced by the space industry, but it is difficult to truly avoid the difficulties faced in the ocean.

Unlike the solar system where there is always a place where the sun can shine, the deep ocean is a dark and claustrophobic place. Not only that, but as the depth increases, the pressure of the sea becomes greater and greater, and the deepest part of the ocean, the Marianas Trench, can even reach a pressure of more than 1100 Pa. At the same time, due to the impermeability of seawater, resulting in the deep sea will only become colder and colder, thus forming a threat to human survival of the three major difficulties: high pressure, low temperature, and no light.

The existence of these three factors, both for people and the probe, is not easy to solve the problem. Therefore, the progress of human exploration of the oceans has been quite slow.

However, with the development of technology, we have also made some exploration of the depths of the ocean, and even several countries have challenged the Marianas Trench, trying to figure out what is in the depths of the trench. But after this expedition, scientists heard strange pairs of sounds in the depths of the trench.

The sound of the Mariana Trench

As humans investigate the ocean, more and more mysterious phenomena appear, so when we have the conditions to explore the Marianas Trench, some scientists will be placed inside the trench can listen to the sound of the seafloor detector, to observe certain phenomena in the depths of the ocean.

After months of "listening," scientists found a constant and steady sound in the depths of the trench, and these sounds of great motion attracted the scientists' attention, and only after they distinguished it was presumed that it might be the sound of swallowing seawater.

To be able to cause such a large swallowing sound, in addition to the blue whale that huge species, other creatures are very difficult to do. But in the depths of the Marianas Trench, again before only a small flounder and coral were photographed, there is no possibility of blue whales.

To figure out where this sound of swallowing seawater came from, scientists from Washington University in St. Louis reinstalled monitoring points in the depths of the trench and analyzed the data returned, at which point they discovered that it was not the creatures that swallowed the seawater, but the Marianas Trench itself, and by their estimation, the Marianas Trench can swallow three billion tons of seawater a year.

Why does the Marianas Trench swallow so much seawater, but the sea level not only did not fall but also gradually rose?

The reason why the sea level is rising instead of falling

The Marianas Trench itself is not only the deepest part of the ocean, but also the weakest part of the entire earth's crust, which indicates that the Marianas Trench is nearest to the soft current layer of the earth.

The soft current layer is the boundary between the Earth's crust and mantle, and the average temperature of the mantle is basically between 6,000 degrees Celsius and 8,000 degrees Celsius, so the soft current layer is also a place of extremely high temperature, which is usually considered to be the origin of magma.

When the Marianas Trench swallowed the seawater into it, it surged into the soft current layer. The Marianas Trench, which is supposed to be at a plate junction, has a lot of crustal activity and thus more frequent volcanic eruptions, which eventually led to the swallowed seawater returning differently.

In addition, some of the seawater is absorbed by absorbent rocks or slipped into other parts of the crust before it can enter the soft current layer, and eventually returns to the sea through hydration reactions.

Because of this cycle, even if the Marianas Trench swallows water continuously, it can maintain the total amount of seawater unchanged.

The real reason for the rising sea level comes from human activities. Once upon a time, the greenhouse effect was only a literal representation of horror to us, but as the urban greenhouse effect has become more and more obvious in recent years, we have felt the changes brought about by rising temperatures more deeply.

In addition to the greenhouse effect feedback in our bodies, the most obvious effect is the polar glaciers. As a place that is not directly exposed to the sun all year round, the Arctic has reached a maximum temperature of 38 degrees Celsius in recent years, while the Antarctic is also getting warmer and warmer, gradually approaching 30 degrees Celsius. Such a marked temperature change has caused the glaciers at both poles to begin to melt as well.

Especially in the Arctic, unlike the Antarctic where there is a huge ice cap pockets, the area of floating ice has become less and less in recent years. The reduction of ice floes not only affects the ecology of Arctic organisms but also intensifies the process of glacial melting.

That's why, even with the "huge appetite" of the Marianas Trench, we often hear scientists worrying about rising coastlines.

Human life requires mainly freshwater resources, and in general, the use of seawater is small, so the coastline is a flat phenomenon in the Earth's internal cycle. However, if the glaciers at the poles gradually melt, the total amount of seawater will only get larger if it is not consumed.

The Earth's area is fixed, when more and more seawater, it can only be through the form of sea level rise on land threats, in this case, the first to suffer is the low-altitude coastal areas.