This noise was very loud. It came from underwater and lasted for nearly a minute. At first, scientists did not think there was anything mysterious about this, but they did not expect that the U.S. Navy, 3,000 kilometers away, would hear a "mysterious sound" coming from the bottom of the South Pacific at the same time. However, where did this strange sound come from?
Today the messenger has circled a useful knowledge point for you: Why does the South Pacific make strange noises?
Welcome everyone to click three times in a row, or press and hold to like
This led scientists to study this "strange noise". However, many years have passed since then. Although similar "strange noises" can occasionally be detected, they have never been able to figure out how it appeared.
Until 2005, scientists conducted acoustic surveys in Antarctica and heard the same noise again. At that time, scientists believed that the source of this strange noise was most likely coming from Antarctica. This also made many people think that this noise might come from an unknown "underwater world."
Because for many years, there has been speculation that in addition to the human world on land, there is another civilization in the deep sea and inside the earth. Therefore, when scientists proposed that the "mysterious loud noise comes from Antarctica", it also made many people who believed that there is an "unknown civilization" in Antarctica feel nervous.
So, what is the truth? Now, 25 years later, scientists have finally found the answer: It turns out that the "mysterious loud noise" that has troubled people for many years is actually related to the rupture of the Antarctic glacier.
So, why is there a "mysterious loud noise" when an Antarctic glacier breaks?
Let us first briefly understand Antarctica: It is located at the southernmost point of the earth. It is a continent surrounded by the Southern Ocean and has no permanent residents. Of course, it is also covered with thick glaciers. From the data point of view, Antarctic glaciers account for more than 80% of the global glaciers.
Speaking of which, before humans discovered Antarctica, Antarctica was completely isolated from the world. No one even knew that there was such a place on the earth full of glaciers. However, after humans discovered Antarctica, over the past 100 years, Antarctica has undergone great changes under the influence of humans and climate.
One of them is that the Antarctic glaciers began to melt on a large scale under the background of greenhouse effect , and the melting rate became faster and faster. Therefore, in 1997, when an Antarctic glacier broke, a "mysterious loud noise" could be detected thousands of kilometers away in the United States.
After years of research, scientists have called this "mysterious loud noise" ice shock . What does this mean? To put it simply, it is a huge shock wave generated by the glacier's own sliding during the process of fracture and detachment. When an "icequake" occurs, its power is actually about the same as an earthquake from the interior of the earth.
And during the research, scientists also discovered that whenever an "icequake" occurs, the seismometer will also detect mysterious shock wave signals, but there is no corresponding earthquake on the earth. Therefore, scientists will confirm that these shock wave signals come from glacier fractures.
At present, the "icequake" concentration area that scientists have targeted is located between the Bransfield Strait and the Ross Sea in Antarctica. The lithological structure here is very complex. There are not only Cenozoic volcanic rocks and metamorphic rocks, but also ancient bedrock and a large amount of sediments. Therefore, when the glacier here breaks, the sound will be emitted from here, and then quickly spread to places thousands of kilometers away, and will be captured by human monitoring equipment.
And scientists have found that in the environment of global warming , such "icequakes" will become more and more frequent in the future. After all, the situation of Antarctic glaciers has become increasingly pessimistic, especially the Thwaites Glacier, known as the "Doomsday Glacier", which is more likely to pose a considerable threat to mankind before the end of this century.
So, what is the current situation of Antarctic glaciers? What impact will it have in the future?
According to scientific research by the American Geophysical Union: In the next five years, the key ice shelves of the "Doomsday Glacier" may completely collapse, which will also cause sea level rise to accelerate. It is very likely that before 2100, the global sea level will rise by about 65 cm.
Moreover, these glaciers have chain reactions with each other, which also means that once this prediction comes true, after the collapse of key ice shelves, the overall stability of Antarctic glaciers will become worse and worse. It is very likely that around 2030, Antarctic glaciers will become like glass and break one after another.
At the same time, a study from the American journal "PLoS Biology" also found that if humans are unable to prevent global warming before the end of this century, then at least 65% of Antarctic native species will not be able to enter the 22nd century with humans.
This is not alarmist, because a scientific study by the Australian National University also found that before 2500, global sea levels will rise by 2-5 meters due to the melting of Antarctic glaciers. What is this concept? If this happens, many coastal areas will be flooded and many people will be displaced.
It can be said that climate change caused by human activities has a very large impact on the entire earth, and may even affect the fate of mankind. Therefore, more and more scientists are calling: We must find ways to prevent global warming. Only in this way can we have a hopeful tomorrow.
Okay, that’s it for today’s program. I am the Singularity Messenger. Follow me. The next episode will be more exciting.
