In Pakistan, one hears every day that the Internet is slow in the country, and one of the reasons for this is often given by Pakistan Telecommunication is that there is a fault in the Internet cables lying at the bottom of the sea. Internet service has been affected due to this.
There are speculations about how Internet cables at the bottom of the ocean become damaged. However, the most interesting idea is that these wires are cut by sharks with their teeth and because of them we lose the internet.
99% of the world’s digital communication system depends on cables laid under the seabed. If these wires are broken, the system of the entire country can be disrupted.
In this BBC report we try to find out how the Internet depends on the behavior of the ocean and does sharks really have a role in it? And once these cables are damaged, how do they go down to the bottom of the ocean and repair them? And how to find out which wire has a problem at which place?
It was 1929 when a magnitude 7.2 earthquake was felt south of Canada’s Beaver Peninsula on November 18. It was five o’clock in the evening. However, residents living on the coast of the Beorn Peninsula, far from the epicenter, suffered no significant damage except for some boats that were overturned by the tremors.
But in the sea far from the shore, a different kind of power was taking hold. Around 7:30 p.m., a 43-foot-tsunami hit the Beaver Peninsula coast. 28 people died due to this destructive wave. Some of them died due to drowning and others due to injuries.
The earthquake caused a lot of damage to the local people, but it also had a severe impact on the sea. The earthquake caused a landslide at the bottom of the sea. According to history, at the time when the earthquake occurred, people did not know about tsunamis, nor did they know that landslides can also occur in the sea.
Actually, when there is an earthquake in the ocean or any kind of geological movement, the plates in its bottom move from their place. Due to this, the water here becomes thick and the pressure of the water in the bottom of the sea increases. Landslides occur because of this, and these landslides are just like snowflakes falling down from a snowy mountain.
This landslide at the bottom of the sea is called ‘turbidity current’ in English. In 1928, the landslide that started from the epicenter of the earthquake covered a distance of several thousand kilometers. The speed of this landslide ranged from 57 to 80 mph.
Although the landslide was not noticed at the time, it left an important clue for the future.
The landslide route was equipped with the most advanced communication technology of the time, also known as ‘trans-Atlantic’ cables. Due to an earthquake in the sea, these wires broke. In 28 locations, 12 wires broke simultaneously while the remaining 16 wires broke intermittently.
This was also a mystery because the wires continued to break from 59 minutes after the earthquake until 13 hours and 17 minutes later. These wires were about 500 km away from the epicenter.
Scientists questioned that if these wires were broken due to an earthquake, then all the wires should have broken simultaneously. But it didn’t happen. Why were these wires breaking one after another
The answer to this question was revealed in 1952 when researchers found out why these wires, spread over such a large area, were breaking intermittently. The farther the wire was from the epicenter, the sooner it would break.
It became clear to the researchers that due to the landslide, there was a strong shock to all the wires lying on the sea floor. The shock was so strong that the strings could withstand the pressure to a certain extent and then broke.
Until then, no one knew about ‘turbidity knots’ because there were records of when these wires broke and the period during which they broke, thus providing information about the movement of waves on the surface and bottom of the ocean. .
Repairing these wires was also a complicated task in this era, but due to their breakage, an unseen phenomenon of nature was revealed to humans.
Over the coming decades, as the network of cables on the ocean floor continued to grow, new scientific discoveries were made about their repair and maintenance. Along with this, we also started getting high speed internet.
Now the speed of internet has become so fast that our daily life, income, health and safety all depend on it and due to dependence on internet our life is at the mercy of these wires.
But when these wires are broken, why does our system go haywire?
Information exchange over internet wires
Currently, there are 1.4 million kilometers of wires lying on the surface of the sea. These wires are present in every ocean and sea.
If one end of the wire is connected to the other end of the wire and measured in length, it will be as long as the diameter of the sun. 99% of our information is carried from one place to another by these wires.
Some people might be thinking that these wires lying in the sea and ocean would be wide and heavy, but surprisingly, most of these wires are about two centimeters wide. Some wires are as wide as household pipes that water plants.
If the Internet wires were to go down as recently as 1929, communication between North America and Europe would be profoundly affected. However, Mike Clare, a researcher working on the marine environment associated with the International Cable Protection Committee, says that ‘the network has become quite strong in the world now.’
‘Every year there are 150 to 200 incidents of wire damage, but compared to the number of wires, these complaints are very few. Most of the problems encountered in these cables are quickly resolved
How does the Internet run through such thin wires and how are these wires protected from destruction?
Since cables were first laid on the ocean floor in the 19th century, we have learned how extreme environmental events, from undersea volcanic eruptions to hurricanes and floods, affect cables.
However, the least damage to cables is caused by natural calamities.
“70 to 80 percent of cable failures are caused by human activities in the oceans,” said Steven Holden of Global Marine, an engineering firm that works on the repair and maintenance of undersea cables.
Steven Holden oversees the cables that provide internet to Europe, the Middle East and Africa. He said that the falling anchor of a ship or boat causes damage to the wires, especially those boat trawlers whose wide nets catch a large number of fish. Most of the times the anchors fall on the wires or the wires get caught in nets.’
Steven Holden said: ‘Such incidents occur mostly at depths of 200 or 300 meters in the ocean, while large commercial fishermen are increasingly entering deeper waters to catch fish. Some of these fishermen have reached a depth of 1,500 meters in the northeast Atlantic to catch fish.’
He says that ’10 to 20 percent of the problems in Internet cables in the seabed are due to natural disasters. In these places, the wires have weakened because the waves keep crashing against the rocks. A problem called ‘shunt faults’ occurs in such wires.
Mike Clare, a researcher with the International Cable Protection Committee, said: ‘The idea that the cable was broken by a shark bite has become a modern-day myth. Yes, it has happened in the past that sharks have damaged wires, but that is no longer the case. Companies use ‘Kevlar’ to make this wire, which makes the wire stronger.’
For deep water, light and thin wires are used so that they can be easily removed from the water and repaired. Think if the wire was wider and heavier, how difficult it would be to pull it out thousands of meters below the sea level.
However, the wires that are laid near the shore are made a little heavier because the wires are more likely to be damaged by getting caught in the nets of ships and boats.
An army of ships ready to repair cables
If there is a problem with the wires somewhere, a ship is sent there.
“All of these vessels are strategically deployed around the world,” said Mick McGovern, deputy vice president of Alcatel Submarine Networks. It takes 10 to 12 days for the ship to move from the port to the place where the stranded wires have to be repaired.’
“That gives you enough time to figure out where the problem is.”
“If you look at how extensive this system is, (a period of 10 to 12 days) is not that long,” he said.
McGovern said it took nine months to repair submarine cables when Canada’s Beaver Peninsula was hit by an earthquake.
‘However, it usually takes one to two weeks to repair these wires at depth. How long it takes to repair the cables depends on where the cables are on the seabed and what the weather is like at the time.’
‘If you think about the depth of the water and the placement of the wires, it’s not such a bad solution.’
However, this does not necessarily mean that the entire country will not have internet for a week.
There are many countries that have more than the minimum required number of wires and the internet speed of these wires is also high. More information is transferred in less time.
Therefore, if one wire breaks or gets any kind of damage, additional wires are resorted to.
Because of this system, if a cable breaks on the ocean floor, most of us won’t notice a difference. Please note that this article may take a second or two longer to load than on normal days.
However, in a serious problem, these extra wires can be used to keep the country online.
In 2006, an earthquake with a magnitude of 7 occurred near the coast of Taiwan. Dozens of wires were broken in the South China Sea due to the earthquake, but some of them remained active.
To repair the wires, a type of winch is lowered from the ship into the water and lifts the wires from the bottom. Attached to this spindle is a drum-like shaft which is rotated by a motor. The string starts winding from this drum.
In a room, the wire is repaired and tested. A signal is sent from the ship to the ground through the same wire to detect whether the wire has been activated or not. If the wire is fixed, it is tied to a ‘buoy’ i.e. an anchor floating on the surface of the sea. A signal is then sent from the ground to the ship to check that both ends of the wire are working properly.
Each optical fiber in the cable is tested when it is certain that both ends of the cable are working properly, McGovern said. It is ensured that the connection is correct and then they are sealed by inserting a ‘universal joint’.
This joint is required to be ‘universal’ so that cables from different companies can work together.
‘This makes life easier for international repair teams.’
After the repairs are made, the cables are laid back into the water table. Where the water depth is low and boat traffic is high, these wires are buried in trenches.
Remote controlled machines dig trenches in the water table in which these wires are laid.
In deep water this work is done by tractors equipped with powerful jets. These subsea tractors are attached to the ship on the surface of the sea. A ship moves on the surface of the water while a tractor digs a trench on the water bed.
Some of these tractors are 50 ton while some places require even heavier equipment.
Mick McGovern said that ‘once a ship had to drive a 110-ton tractor in the Arctic Ocean. The wires were laid by this tractor at a depth of four meters in the bed while this tractor had enough power to cut even the frozen snow for at least two years.’
How do stars help us at the bottom of the ocean?
In the 19th century, when cables were laid and repaired on the seabed, many new things emerged. Seeing this, scientists started using these wires for the purpose of research.
At the bottom of the ocean, the wires acted as the walls of the mine.
As the cables were being laid in the Atlantic Ocean, workers noticed that the water depth in the middle of the ocean was decreasing. This revealed that there is a mountain in the Atlantic Ocean which was named ‘Mid-Atlantic Ridge’.
Today, through these wires used for telecommunication, we know in which part of the ocean there is a whale or a ship or an earthquake or a storm is brewing.
Mike Clare of the International Cable Protection Committee says that the damaged cables give the company ‘new information about the dangers in the deep sea.’
“If the cables were not damaged, we would never have known that there was a volcanic eruption on the ocean floor that caused a landslide in the ocean.”
In some places, however, climate change has exacerbated the problem.
For example, consider the Congo River in West Africa. Day by day floods increase the amount of silt in the river, which then flows into the Atlantic Ocean in large quantities. Due to this, the wires are getting damaged a lot.
“We now know that the wires have to be laid some distance from where the river meets the sea,” McGovern said.
However, according to experts, it will be impossible to protect wires from some damages in the future.
In the year 2021 and 2022, a volcano called Hanga Tonga Hanga Hapai erupted at the bottom of the Pacific Ocean. Its eruption knocked out all the cables giving Tonga internet access.
It took five weeks to fully restore internet in the country, while temporary internet service was restored in some places within a week.
Steven Holden of Global Marine Engineering firm says the magnitude of the Hanga Tonga eruption was ‘extraordinary’. However, running internet cables to any island that is near a volcano is not without its risks.
However, many countries use multiple wires so that if one wire fails, another wire can be used in its place. Other wires can be relied upon if ever there is a crisis.
Mike Clare, a researcher at the International Cable Protection Committee, said: ‘This shows how much diversity we need in cable routes, especially for small islands in the South Pacific where typhoons, earthquakes and volcanoes are more prone. Eruption is common. These places are being affected by climate change in different ways.’
Steven Holden of global marine engineering firm, says, ‘As shipping and fishing continue to improve, damage to cables may be reduced.’
An ‘automatic identification system’ installed on ships lets you know where anchoring can cause cable damage. Some firms are now offering services that let ships know in advance where to begin slowing down to anchor safely.
However, in places where the fishermen’s boats are not so modern and their crew is less, their anchoring causes damage to the wires.
“People need to be made aware in places like this,” says Mike Clare. They should be told where the wires are laid.
“It’s in the interest of all of us to keep the internet going”
(https://www.bbc.com/urdu/articles/czxgq2j700do) By William Park BBC News
