I don't know how long the hydrogen sulfide layer has been precipitated, and Li Huan descended fifty meters before penetrating the hydrogen sulfide layer. The spherical enchantment formed by the storm island and reef necklace was like a bubble, squeezing out of the hydrogen sulfide layer with Li Huan's "wave", just because of this layer of enchantment, the hydrogen sulfide precipitation did not cause any harm to Li Huan.

However, after passing through the hydrogen sulfide layer, it was pitch black underwater, and even the lighting rods were not very effective. However, the scan of the handset showed that the space after leaving the blue hole suddenly became wider, and it seemed to be boundless.

"Xiao Fei, give me the data here, where have I been......" Li Huan hurriedly called Xiao Fei in the spiritual power channel.

Xiao Fei's speed was extremely fast, and he captured that Li Huan had just passed through two ground penetrating radars above his head, and at the moment he made a cameo appearance as a hacker hacked into two satellites, and when the Doppler power was fully turned on, Li Huan finally knew where he was. After Xiao Fei repeatedly surveyed and mapped this underwater world, he had a rough topographic map. How did the Blue Hole really connect the waters outside, in fact, it was not the connection, but the fact that this island was suspended on one side!

The island resembles the shape of a rolling wave, but the "wavehead" where people live today is lava from volcanic eruptions under the sea.

Probably many, many years ago, there was a super submarine volcanic eruption in this area, and the lava erupted from the bottom of the sea went straight up hundreds of meters to the sea surface, and after cooling on the sea surface, it formed the shape of an island and reef, and it itself was hollow underneath, like the figure of "7", a thick cooling lava supported the entire island, and people lived on the "horizontal" of the figure 7.

Seeing the terrain here, Li Huan couldn't help but sigh how violent the volcanic eruption had to be to send magma to the sea surface hundreds of meters away, and the creations of nature were really wonderful. If you see the terrain clearly, then the secret of the blue hole will be solved, it is not a "volcanic tube" at all, it is not wrong to say that it is a "volcanic tube", it is just a "horizontal" on the figure 7, because when the sea water rapidly cools the lava, it is just a ventilation tube.

Above the hydrogen sulfide layer is the rainwater and fresh water that has accumulated on the island for thousands of years, and under the hydrogen sulfide layer is naturally the ocean.

"I didn't expect it to be such a terrain......" Li Huan muttered to himself.

No wonder no one has ever discovered that the thickness of the stratum below the island of nearly 400 meters can not be imagined to be a figure 7. If I hadn't accidentally stumbled downstream from one direction in the blue hole, about two or three hundred meters, I would have the idea of giving up.

Li Huan was thinking that he was lucky, and he accidentally dived this piece of water, intending to continue descending to see what was below, when suddenly his feet were cold, and a strong current of water washed him out more than ten meters away. When he stabilized his body, he looked down, but there was nothing. Li Huan groaned for a while, counting the lighting rods in his virtual space, this is still left from the time when he was in Antarctica, after diving in the blue hole just now, there are probably more than a hundred.

"What the hell...... Li Huan folded all the lighting rods at once, returned to the position where he had just been impacted, and threw down a large number of lighting rods. The effect of this kind of thing is very limited when there are no reflections around in the open sea water, but a large number of lighting sticks still let Li Huan see a strange scene that he has never seen before.

As soon as the one hundred and ten lighting sticks landed on the position where Li Huan was washed away just now, they suddenly seemed to be pulled by some powerful force, and they were quickly rushed away a hundred meters away, turning into a small point of light, and the speed was staggering. Just when Li Huan thought that these lighting sticks were going to be taken farther away, those small points of light suddenly turned around and circled back, but not towards Li Huan, but in a further direction. After a turn, the 100 rods suddenly split into two strands, then into four strands, then eight, sixteen, and thirty-two...... Soon Li Huan saw the trajectory of these lighting sticks being washed away. They were carried by the strong current of water in a constant circle, and all the light was connected, and they actually formed a semicircular "cover" under the water, which was upside down dozens of meters under their feet.

The "hood" formed by the blue, green lighting rods resembles a crystalline palace that completely envelops the underneath.

"Brother Huan, what is this, why did you turn the lighting stick like this?" Although this "palace" looks bewitching and beautiful, the speed of the lighting rod also knows that this sudden flow of water is not easy to provoke.

Li Huan measured the speed of the lighting rod forward, and the speed of the lighting rod dragging the light track was even 90 knots per hour when it was hit by the current. With such a current intensity, even if Li Huan had a storm island and reef necklace, he couldn't cope with it at all. Even driving a submarine outside is only a dry stare.

"It's undersea turbulence, and it's a downstream, so it's a problem. Li Huan frowned.

Turbulence, also known as turbulence or turbulence, refers to an irregular movement of water. In the movement of turbulence, the path of each turbulent micromass is not neat and parallel, but extremely complex and different curved paths, and the velocity distribution of turbulence micromasses is not stable, but fluctuating and undulating. Turbulence is divided into air turbulence and water turbulence, air turbulence has generally been encountered by people who have taken an airplane, the plane flies well, suddenly a sudden turbulence, suddenly up or down, the light is injured, the aircraft is damaged. Fortunately, the general air turbulence does not have such a big effect.

Underwater turbulence is hundreds of times more dangerous than air turbulence, and there is an airplane on top of the air turbulence, and if you encounter ocean turbulence in the sea, the danger is fatal.

And the most dangerous of all underwater turbulence is the downstream.

The so-called downflow is a very strong downstream, which often occurs in 20-30 meters deep seawater, and an inattentive can take a person to a depth of 50 meters or more in a matter of seconds. Moreover, the appearance of downstreams is often sudden and intermittent, and unprepared divers can easily be caught off guard, resulting in unfavorable responses. In the process of countering the strong downdraft, people need to lose a very large amount of air, sometimes with little effect.

Finally, the lack of air, combined with being at great depths, can pose a great potential threat.

Although Li Huan doesn't have to think about the air problem at all, and the turbulence will not cause too much danger to Li Huan, the turbulence speed is too fast, Li Huan can't pass through it directly, and there should be no turbulence at this depth, even if he is unlucky, the turbulence is unstable, and he has never heard of any turbulence that operates in a semi-circular way. Even if it operates in a semi-circular way, its speed is too amazing, the most powerful current directly on the Mexican Current, the flow speed is only 9 knots per hour, and the speed of the current running with a lighting rod under Li Huan's feet has reached 9000 miles per hour, which is ten times faster than the Mexican Current.

There must be a demon when things go wrong, even if Li Huan can not care about the supply of air, he does not dare to approach this turbulence easily.

Even if you rush in with your head iron, who knows what the hell is inside? Can something that stir up such a strong ocean current be easy to deal with?

Li Huan pondered for a while, and finally let Xiao Fei determine the three-dimensional coordinates, and decided to go back the same way first, and ask a few hooligans of the Sea Serpent Gang, or Laila's mother and daughter, if they have heard of this strong turbulence underwater, maybe there is a solution. Expedition is one thing, if this is on land, Li Huan rushed in without saying a word, but at a depth of four hundred meters, it is not a joke, refining qi or not, there is not much difference.

400 meters below water, according to the pressure of 10 meters of one atmosphere, plus the normal pressure on land, that is, 41 atmospheres. One atmosphere is one kilogram of force per square centimeter, and according to this calculation, the pressure of 400 meters underwater is about the size of a face, and it will bear a force of 4 tons, which is about two cars.

The face of the refiner is not made of steel......

……

When Li Huan floated up along the Dragon Cave, he had been in the water for more than five hours.

Seeing Li Huan coming up from the Dragon Cave, Leila's two mothers and daughters finally put down their hearts that mentioned their throats.

But then Li Huan's question blinded them all, what kind of undersea turbulence...... Laila and her mother are still stuck at the level where the water of this blue hole is poisonous, how can they possibly know what undersea turbulence is. Only when Li Huan said this, Frank's face changed, but he quickly turned to normal, as if he hadn't heard anything.

Although Frank's face changed quickly, Li Huan still caught the clue.

"I advise you to be honest, it looks as if you know something. Li Huan looked at Frank coldly: "Otherwise, I will let you sleep forever, and throw you off the twin lakes, you can choose for yourself." ”

Under Li Huan's strong threat, Frank finally chose to be honest: "Master Wizard, it's not that I don't tell you, it's because I'm not sure about this matter, I just heard my grandfather talk about it, he is a fisherman, he has been fishing in the nearby waters all his life." ”

"Then why don't you learn from him to be a fisherman, what kind of hooligan are you going to be?" Li Huan sneered: "Okay, you tell everything you know, and it's my business to judge right and wrong." ”

Frank had no choice but to tell the truth.

The fishermen of the Azores are very strange, they have a strange rule not to fish within the limits of the archipelago, and would rather sail farther to the sea than cast their nets in the Azores. According to them, under the water of the Azores, there is a very large coral city, the range is so large, more than a hundred hundred miles, covering the entire Azores, it is absolutely impossible to cast a net, otherwise it will anger the sea god and drag the nets and boats down.

I don't know how many hundred years of this rule has been circulated, and I don't know who passed it down, but people who work at sea have a characteristic, that is, they would rather believe it, so everyone has always followed this rule, but nothing has ever happened.

However, over time, in the 80s, a large number of wooden ships were decommissioned, and mechanical ships made of steel with good watertightness became popular. Steel-made ships have advanced equipment and good safety, so some people start to itch. You must know that when you go to the open sea to fish, the cost of oil is a big expense, and no one has been netted near the archipelago for hundreds of years, and the fish are dense, so fishing here is naturally more in line with the laws of economy. So the captain of a fishing boat called "Ostrea" had the audacity to catch fish by trawling at the bottom of the bottom, and as a result, the steel fishing boat of more than 300 tons seemed to be pulled by something and dragged under the water.

Fortunately, the fishing boat was fully equipped, and the crew on board were all experienced sailors, and with the oxygen cylinders stored on the ship, they escaped before being dragged into the deep sea, and the surviving crew described it as this, Osterrea was pulled into the water by the strange current, and in the place of the wreck, they could still see the blue crystal light flashing on the bottom of the sea, and the scene was like seeing a crystal palace on the bottom of the sea.

The blue crystal light, Li Huan groaned for a while, this is probably the glare caused by the small-scale eruption of the volcano under the sea, although the lava is dark red, but with the movement of the earth's crust, natural gas will also gush out in large quantities, and the natural gas and lava will burn together, which will form a blue dazzling.

However, Li Huan did not interrupt Frank and listened to him continue.

After the sinking of the Osterea, people from the local fishing association tried to salvage the wreck, and as a result, the salvage boat was also towed to the bottom of the sea. This is no ordinary marine accident, in order to find out what lies beneath this sea, the people of the fishing association invited foreign experts to use advanced sonar imaging to probe the seabed, and the conclusion was surprising that nothing happened.

There is nothing to say here, it is really "nothing" in the sonar range, there are no schools of fish, no undulating terrain, no legendary coral cities, not even shipwrecks are gone. Judging from the sonar image, the seabed here looks like an open field of platforms, and there is not even a small rock.

This is impossible, because the survivors on the Osterella clearly saw the turbulence, and the underwater turbulence is generally caused by the complex underwater terrain and different flow speeds, and no one believes that this is a flat land. And what about the old underwater cities? There's no way to explain it.

After several explorations, foreign experts were also confused, and finally in order to save their own face, they reluctantly gave an explanation of "tidal turbulence".

The so-called tides, that is, the rise and fall of the tides caused by the gravitational pull of the moon and the sun, are periodic fluctuations. Because the Moon and the Sun are different from the Earth, the Moon's gravitational pull is stronger than that of the Sun, so the size of the tides generally follows the rise and fall of the Moon. However, the moon has been orbiting the earth for an unknown number of years, and all the periodicity has been proven, so the tides affected by the moon are also very regular.

Fishermen all look at tidal operations, and if you want to say that tidal turbulence is better than experts, fishermen know better than experts, and this explanation is obviously difficult to cover everyone's mouths. Everyone thought that they had invited a team of impostors, so after driving this group of people away, they invited a group of experts, although the rhetoric was still different, but one thing that both groups of people were very sure of, that is, there was nothing at the bottom of the sea, and it was mediocre.

I tossed and turned like this several times, but I never found out what was under the water.

But the dwindling number of fish in the open sea emboldened the fishermen to explore, and after sinking a dozen ships of various tonnages, everyone groped for the exception of the experience that as long as the waters of the Azores were safe at low tide, no matter how much the net was pulled, there would be no problem. But as long as the tide rises, whoever dares to go down the net will definitely be dragged to the bottom of the sea.

Li Huan suddenly realized, no wonder the legend says that when the moon rises, you will see the underwater city, and the tide is the easiest to rise and fall when the moon is full.

Li Huan calculated the time, wasn't it just two o'clock in the morning the last time the tide ebbed? He thought about it, and asked Laila and the two mothers and daughters to go down the mountain and go back to the military base to wait, and the hooligans of the Sea Serpent Gang were naturally knocked down by another mental shock. He planned to wait here, wait until about two o'clock in the morning, and go directly to the sea from the Blue Hole.

Finally, at about two o'clock in the morning, Li Huan counted his equipment and jumped into the blue hole again.

In order to catch a glimpse of the possible ruins of Atlantis, a mountain city thousands of miles away, Chen Xue and Fiona have not slept until now, just like staying up late to catch up on dramas. Li Huan may solve the biggest mystery under the sea for thousands of years, discover the largest underwater ruins in the history of Europe, and go to sleep without witnessing the moment of discovery, it would be too stupid.

It doesn't matter if the lighting stick is gone, it really doesn't work to use the infrared night vision of the submachine, although it is not as colorful as the naked eye, but in terms of clarity, the infrared vision is clearer. Diving into the Blue Cave twice in one day, Li Huan immediately noticed the difference, and sure enough, at low tide, the water level of the Blue Hole also dropped a lot.

After Li Huan activated the barrier of the Storm Island Reef Necklace, he plunged into the Blue Hole, and soon, he descended to a position about three hundred meters underwater, but at this time, the layer of sediment was gone. Li Huan thought about it for a while, and immediately figured out the truth, when the sea water is at low tide, the water level in the blue hole decreases, and the water pressure inside and outside the cave is different, and the water level of the blue hole naturally recedes faster when the tide falls, just pushing the layer of hydrogen sulfide sediment out of the outlet under the blue hole.

When the tide rises, the sediment will pour back into the Blue Hole due to the rising water, which is why the legend says "see the city under the Twin Lakes under the moonlight". Although Li Huan felt that he had figured it out, it was not like this, and he had to go down and see it in person.

Li Huan quickly dived down the blue hole and emerged from the underwater exit.

Underwater, the upside-down "semicircle" current has still not subsided, and the lighting rods that Li Huan got from his trip to Antarctica are all military-grade lighting rods provided by Bellamy, and it is not a problem to shine for a day. The lighting rod was swept by the ocean current and still ran according to the trajectory that Li Huan saw in the afternoon, but the speed was much slower.

There's a door!

The descending turbulence is like a natural barrier, when the tide rises in the afternoon, it rolls at a very fast speed, and when the tide is low at night, the direction of the current may be subtly changed by the water level that has dropped more than ten meters, resulting in the turbulence slowing down The ocean current is clueless, and sometimes an unprovoked wave on the sea surface can set off an underwater storm.

Li Huan tried to get close to the current, because there was a lighting rod outlining the direction of the current's movement, so he could approach carefully this time. Approaching the current, it was inevitably swept out of the distance, but much better than the unreasonable impact of the afternoon. In the afternoon, the speed of Gada is the current in the sea is not reasonable at all, even if Li Huan is good at water, he no longer needs air, but as long as he is swept into the falling turbulence, he can't stabilize his body at all. It's like a good long-distance runner, you let him race blindfolded, and he never wants to reach the finish line in this life, and it's already God forbid if he doesn't run backwards.

However, it is also because of this downward turbulence that until now, what is under the turbulence is still an unsolved mystery.

In order to further stabilize his body and enter the ocean current, Li Huan pinched several aura masses, and once he couldn't stabilize underwater with his skills, he detonated an aura mass to fight against the ocean current.

After holding several spiritual qi masses in his hand, Li Huan tried to enter the turbulence in the direction of the descending current, and entered the ocean current, and sure enough, it was the same as he thought, and he was immediately washed around, if it weren't for the fact that he held several spiritual qi masses in his hand and detonated in time to resist the impact of the current, Li Huan might have been washed directly to Java.

"Brother Huan, you have to be careful, it's really not good, we won't look for this place. Chen Xue watched Li Huan detonate the aura mass again and again to stabilize his body, and it was not very stable, and couldn't help but say worriedly: "I checked the tide table in the afternoon, the real biggest low tide, we have to wait until November, it's really not okay, we will come back in November." ”

"I know, you said it was the low tide of the year, but not now. Li Huan replied: "Don't worry, I know in my heart, as long as there is no problem with oxygen, how can I find a way to get out." ”

Li Huan detonated the aura mass to stabilize his body against the impact of the ocean current, and at the same time quickly passed through the thick descending turbulence. This turbulence is even more powerful than Li Huan estimated at the beginning, the ocean current outside the turbulence circle took Li Huan out of more than ten meters away with just a light wipe in the afternoon, although it was much calmer than in the afternoon, but when Li Huan broke into the current circle, he really understood what is called "the majesty of nature".

The chaotic currents didn't know how they were colliding around, and in Li Huan's ears, he could only hear the roaring sound of the waves, and the surging movement of the ocean currents was even more unreasonable, no matter what he caught, it would be used to "strengthen defense". In the infrared vision, Li Huan clearly saw that in addition to his own lighting rods, there were also many sharp stones in the current.

But fortunately, three minutes later, Li Huan successfully penetrated the turbulent layer.