The unfolding tragedy amid the crumpled buildings of south-east Turkey and northern Syria highlights how unexpectedly earthquakes can strike. Scientists are searching for ways to spot the early warning signs of these most unpredictable of natural disasters.

They hit suddenly and without warning. The two devastating earthquakes that struck south-eastern Turkey and northern Syria have claimed thousands of lives and left many more injured or without shelter. Occurring in the early hours of 6 February, most of the victims would have been inside sleeping when the first 7.8 magnitude earthquake brought their homes crashing down on top of them.

The first Indication semiologists had that a major disaster was unfolding were the abrupt flashes of activity on their sensitive instruments spread throughout the world as the seismic waves produced by the first earthquake reverberated around the globe. A few hours later this was followed by a second large earthquake of 7.5 magnitude.

The relative shallowness of both quakes meant the intensity of the shaking was particularly severe. And as the area continues to shudder with aftershocks, experts at the United States Geological Survey have warned that those who survived, and the rescue workers now flocking to the region to help, face significant risks from landslides and ground liquefication as a result of the shaking.

But as the world races to provide aid to the shattered communities on either side of the border between Turkey and Syria, some are wondering why we didn’t see this coming.

The East Anatolian fault system where the earthquakes occurred is part of a tectonic “triple junction” where three tectonic plates – the Anatolia, Arabia and Africa plates – grind against each other. Since 1970, only three earthquakes of magnitude 6 or larger have hit the region, and many geologists believed the region was “overdue” for a large earthquake.

So, why could they not predict it?

In truth, the science of predicting earthquakes is very, very difficult. While there are often minute signals that can be detected in the seismic data after an event has happened, knowing what to look for and using that to make forecasts beforehand is far more challenging.

“When we simulate earthquakes in the laboratory we can see all these little failures happening – there is some cracking and some flaws that appear first,” says Chris Marone, a professor of geosciences at Sapienza University of Rome, in Italy, and Penn State University in Pennsylvania, US. “But out in nature there is a lot of uncertainty about why we often don’t see foreshocks or indications that there is going to be a big earthquake.”

Geologists have been trying to use modern scientific methods to predict earthquakes since at least the 1960s, but with little success. Much of the reason for this, says Marone, is the complexity of the fault systems that criss-cross the globe. There is also a lot of seismic noise – the Earth is constantly grumbling and rumbling away, which, when combined with the anthropogenic clatter of traffic, building work and daily life, makes it hard to pick out clear signals.

According to the United States Geological Survey, it takes three things to produce a really useful earthquake prediction – the location where it will happen, when it will happen and how big the event will be. So far, they say, no one can do that with any certainty.

Instead geologists produce what are their best guesses in “hazard maps” where they calculate the probability of an earthquake within a timeframe of several years. While these can help with some degree of planning, such as improving building standards in the areas most at risk, it doesn’t provide the level of prediction needed to provide early warnings to the public to allow them to evacuate or take shelter. And not everyone who lives in an earthquake zone can afford the kind of infrastructure needed to withstand large amounts of shaking.

“In Turkey and Syria, there were a lot of factors that meant buildings were in a state where they were ready to pancake and fail,” says Marone. “In a lot of the Western world there have been seismic reinforcement codes that were implemented in the 1970s and 1980s. But it costs a lot to build and retrofit buildings.” (Read about how Japan’s skyscrapers are built to survive earthquakes.)

So, scientists have instead been searching for ways to make earthquake predictions more accurate. Alongside seismic signals, researchers have searched for clues in a wide variety of places – from the behaviour of animals to electrical disturbances in the Earth’s upper atmosphere.

Scientists in China have been looking for ripples in electrically charged particles in the Earth’s ionosphere in the days leading up to earthquakes

Recently, however, there has been growing excitement around the capabilities of artificial intelligence to detect the kind of subtle signals that humans miss. Machine-learning algorithms can analyse vast amounts of data from past earthquakes to look for patterns that might be used to predict future events.

“This kind of machine-learning-based prediction has produced a lot of interest,” says Marone. He and his colleagues have for the past five years been developing algorithms that are capable of detecting failures in simulated earthquake faults in the laboratory. Using fist-sized blocks of granite, they can recreate the stress build up and friction that might occur at a fault, building up pressure until the fault slips, creating what they call “labquakes”.

“Elastic waves travel through the fault as it breaks little by little,” says Marone. “We can predict when the failure is going to occur in the laboratory based on these changes in elastic properties and the noise coming from foreshocks in the fault zone itself. We’d love to port this to the Earth, but we are not there yet.”

Transferring this predictive power of AI to the larger, complex environment of real-world fault zones is far more challenging.

“There are a few cases where people have figured out how to do it in post-prediction after an earthquake which suggest this might work,” says Marone. “But there’s not been a big breakthrough yet.”

Scientists in China, for example, have been looking for ripples in electrically charged particles in the Earth’s ionosphere in the days leading up to earthquakes caused by changes in the magnetic field above fault zones. One group led by Jing Liu at the Institute of Earthquake Forecasting in Beijing, for example, said it could see disturbances in the atmospheric electrons above the epicentre of the earthquake that hit Baja, California, 10 days before it hit in early April 2010.

Another group based in Israel recently claimed to be able to use machine learning to predict large earthquakes 48 hours beforehand with 83% accuracy by examining the changes in electron content in the ionosphere over the past 20 years.

China is clearly placing its hopes in these clues in the ionosphere. In 2018, China launched the China Seismo-Electromagnetic Satellite (CSES) to monitor for electrical anomalies in the Earth’s ionosphere. Last year, scientists at China’s Earthquake Network’s Centre in Beijing, claimed to have found drops in the density of electrons in the ionosphere up to 15 days before earthquakes that hit the Chinese mainland in May 2021 and January 2022.

“An energy transfer can occur between the lithosphere and the two layers above – that is the atmophsere and the ionosphere,” says Mei Li, one of the researchers working at the China Earthquake Network Centre. But she says the mechanism for how this occurs is still controversial. And she warns that even with the satellite data, their findings are still a long way from being able to predict an Impending earthquake.

“We cannot specify the right location where a forthcoming event will happen,” say the researchers, in a paper about their findings. Li also points to another complication – large earthquakes can induce changes in the ionosphere far away from their epicentre, which makes confirming the precise location difficult.

“The ionospheric anomaly can appear around the epicentre of an earthquake as well as its magnetically conjugated point in the other hemisphere, which gives us more difficulty to confirm the location of the forthcoming event,” she says.

ANIMAL PREDICTION

Reports of animals being spooked and fleeing in panic before earthquakes date back millennia, but using these observations in a meaningful way is difficult.

Animals’ behaviour doesn’t always allow accurate prediction. There are reports of one earthquake being predicted in China several decades ago with the help of unusual animal behaviour, but the feat has never been repeated.

Scientists at the Max Planck Institute of Animal Behaviour in Germany, however, are logging the behaviour of cows, sheep and dogs in earthquake-prone areas of Italy. Animals altered their behaviour earlier the closer they were to the epicentre of impending tremors and earthquakes, the researchers say. (Read more about the animals that predict disasters.)

Other researchers are pinning their hopes on different signals. In Japan, some claim to be able to use changes in water vapour above earthquake zones to make predictions. Tests suggest these predictions have 70% accuracy, although they can only say an earthquake might happen at some point in the next month. Others have been trying to use minute ripples in the Earth’s gravity that can occur before a quake.

But despite all these claims, none have been able to successfully predict where and when an earthquake will occur before it happens.

“We just don’t have the infrastructure to do the kind of monitoring we would need,” says Morone. “Who is going to put up $100m (£83m) to install a set of seismometers of the sort we use in the lab to monitor a fault? We know how to predict laboratory quakes, but what we don’t know is if they really transfer to the complexity of real-world faults. The East Anatolian fault, for example, is in a complex region of the world – not one simple fault plane but a bunch of things coming together.”

And even with the ability to make better forecasts, there is still the question of what to do with the information. Until the accuracy improves, evacuating entire cities or asking people to stay out of at-risk buildings could be costly if mistakes are made. But Marone looks to the world of meteorological forecasting for some indication of what might happen if the data improves.

“They already predict big weather events with some accuracy in advance,” says Marone. This allows government agencies to prepare emergency responses to events such as hurricanes and issue warnings to members of the public that can help keep them safe. Being able to do something similar for earthquakes is still years away, says Marone. “We are not anywhere near that at the moment.”

One area where artificial intelligence may have a more immediate role to play is in the events that happen immediately after an earthquake. Researchers at Tohoku University and Renmin University of China have been developing tools that use AI to classify the damage caused by natural disasters from satellite imagery so governments and rescue teams can be sent to where they are most needed. It uses algorithms to assess building damage and identify the structures which have been totally destroyed or are potentially dangerous.

There are also hopes that machine-learning algorithms might help keep rescue workers and survivors of earthquakes safe by helping to better predict aftershocks that follow a major earthquake. These can pose an enormous risk by shifting buildings left unstable by the initial earthquake, causing further destruction

Researchers at Harvard University, for example, have been deploying deep learning – a form of machine learning – to study patterns of aftershocks in the hope they can be predicted.

“We have a very good understanding of what happens after a big event and why aftershocks occur,” says Marone. “But it’s still not complete. We have got better at knowing as a scientific society if smaller shocks might be leading up to an even bigger one, but there is always uncertainty.

“You don’t need to know very much about earthquakes and aftershocks to realise what happened in Turkey is a very unusual situation where you had two really big earthquakes close to one another. The second one was triggered by the first one, but these were two big main shocks.”

As you read this, around 10,420 giants are heaving their way across the world’s oceans. Their enormous metal bodies lumber onwards in spite of inclement weather and rough seas.

In their bowels, these beasts are carrying 3.8 billion barrels of crude oil among them, enough to fuel around 418,000 transatlantic flights and for the world’s cars to cover around 3 billion miles between them. Their sticky cargo is the raw material for billions of plastic bags, combs, trainers, drinking straws, synthetic clothing, toys, water bottles and hundreds of other plastic-based goods that we use in our daily lives.

There are few vessels that better symbolise the achievements and the problems of our thirst for fossil fuels than the oil tanker. Their number include some of the largest moving human-made objects on the planet – vessels of intimidating scale. Without them, our modern lives would grind to a halt. But as they chug relentlessly across the oceans, these supertankers release their own thick plumes of pollution into the atmosphere and, on occasion, into the water.

In a world where climate change poses a very real threat – one that could force us to wean ourselves off our fossil fuel habit – the diminishing demand for oil tankers could produce new problems. As renewable energy, bio-based plastics and other sustainable materials reduce our reliance on oil, what will we do with the gigantic vessels that currently carry it around the world?

There are some who believe these dirty monoliths of the oil age can be rehabilitated by transforming them into sources of clean, renewable energy

Like most sea-going ships, they could be sent to the scrapheap, their bodies cannibalised for valuable metal that can be melted down and reused. But disposing of them is a dirty, dangerous and poorly paid business for those who undertake this work in some of the most deprived parts of the world.

There are some, however, who believe that these dirty monoliths of the oil age can instead be rehabilitated – they want to transform them into sources of clean, renewable energy. Engineers believe it is possible to use the vast hull of oil tankers to create floating power stations that can convert the ocean swell into electricity. This is the ambitious plan to create the world’s first “waveships”.

“The current problem with most wave energy projects is that they are fixed in place, close to the shore so they can be connected to the electricity grid,” says Andrew Deaner, managing director of ShipEco Marine, the company behind the waveship project. “This isn’t necessarily where the best waves are. With a ship you are mobile, so you can move to the edge of low-pressure weather systems where the waves are bigger and there is more energy.”

Transforming a supertanker into an environmentally friendly mobile power station draws on other areas of the oil industry for its inspiration. Growing up, Deaner spent a great deal of time on diving support vessels built by his father for installing and repairing oil wells and pipelines on the sea bed. These vessels have special chambers cut through their hulls, known as moon pools, which allow divers and submersible vehicles to be lowered safely into the ocean.

On choppy seas, the water levels in these moon pools can move up and down as waves pass along the length of the ship. This in turn can change the air pressure inside the chamber above the pool of seawater as it rises and falls.

“It works like a giant piston,” says Florent Trarieux, a renewable energy engineer who led tests on the waveship concept in scale models at Cranfield University. “We would put a turbine at the top of the chamber that is driven by the air as it is pulled back and forth by the water. We could put these in columns all down the length of a ship like an oil tanker.”

While cutting holes in the bottom of a ship might not seem like the smartest move, tests by Trarieux have shown the huge displacement that oil tankers generate would help to ensure they remain buoyant. Depending on the hull size, the team believe a tanker could have a capacity to produce between 10 and 30 megawatts of electricity. A very large tanker could have up to 35 moon pools, each 20m in diameter, they say.

The technology needed to do this is far from pie-in-the-sky. In the 1970s the Japan Marine Science and Technology Center built a boat shaped buoy that used air turbines at the top of 22 bottomless chambers cut into the hull. But tests of the vessel, which was anchored in the Sea of Japan, showed its ability to absorb energy from the waves was “disappointing”.

More recently, however, engineering giants Siemens have developed a more efficient “hydroair” turbine that can turn the oscillating flow of air inside a water filled chamber into electricity. Another firm, called Ocean Energy, has also built buoys that use a similar principle that are being tested in the Atlantic Ocean.

Like many other wave energy devices, these systems are mounted on platforms that are moored in place and so rely upon the weather at a single spot in the ocean to generate sufficient waves. Wave energy generators also need to be able to transmit the electricity they produce back to shore, and so need to be close to the coast so they can be connected through cables.

Putting oscillating air flow turbines above moon pools on board ships could allow them to chase storms around the oceans to get the best waves

Deaner and Trarieux, however, believe this is limiting the potential of wave power. They say that putting oscillating air flow turbines above moon pools on board ships could allow them to chase storms around the oceans to get the best waves.

“Effectively we would be going ‘fishing for energy’,” says Trarieux. Out on the open ocean where unimpeded winds can generate larger waves, the amount of energy that can be generated is many times greater than can be produced in coastal areas. “It is a completely different approach to wave energy.”

The project has already received the backing of the UK government, which funded some of the feasibility studies and scale model tests. These have shown that the tankers can be modified to create moon pools without compromising their strength and stability, according to Trarieux.

The next challenge Is getting hold of a suitable ship. Second-hand oil tankers are not cheap and even an ageing, relatively small ship can cost millions of dollars on the open market. But the team believe the prevailing wind could work in their favour as the world moves away from using fossil fuels.

All that steel could be cut up and reused, or we could repurpose them to make wave energy – Florent Trarieux

“There are thousands of oil tankers currently in operation and hundreds reaching the end of their service lives every year,” says Trarieux. “All that steel could be cut up and reused, or we could repurpose them to make wave energy.”

The number of large oil tankers being scrapped reached record levels in 2018, with more than 100 vessels being sent for demolition. The majority ended up on beaches in Bangladesh, India and Pakistan where they are taken apart by unskilled workers, often with little or no safety equipment. The life expectancy of those doing this dangerous work at these enormous shipbreaking yards has been estimated to be 20 years lower than the general population in these countries and the industry has faced accusations of human rights abuses. Environmental campaigners have also raised concerns about the hazardous substances and pollutants that leach out from the ships as they are dismantled, which has led to calls for stricter environmental regulations around ship breaking.

Converting these vessels into waveships could be a tempting alternative to scrapping them. “Transforming old oil tankers, used to ship millions of gallons of oil around the world, into a potential clean energy source is yet another example of the UK leading the global shift to clean growth,” says Claire Perry, energy and clean growth minister in the UK.

If someone wanted to put a chocolate factory on the deck of our waveship we could actually be manufacturing products as it is being shipped to markets around the world – Andrew Deaner

But Deaner’s vision goes beyond simply turning them into power stations where the energy will be stored on board in expensive, heavy batteries. Instead, he sees these giant ships becoming floating, self-sustainable factories by putting the electricity they produce to immediate use.

“We are looking at making products onboard so we are not tied to any electricity grid connection,” he says. “We are looking at producing fresh water – we think we could make somewhere between 18,000 and 36,000 tonnes a day before bringing it ashore. We could also make hydrogen or liquid nitrogen, which we could sell to industry.

“But if someone wanted to put a chocolate factory on the deck of our waveship we could actually be manufacturing products as it is being shipped to markets around the world.”

But not everyone is convinced by the idea. Stephen Salter, a leading wave energy expert at the University of Edinburgh who invented one of the early wave energy devices commonly known as Salter’s Duck, says air turbines may struggle to cope with the wide range of flow speeds caused by natural waves on the ocean. He also worries about how resilient an oil tanker would be on the high seas with holes cut in its hull.

“Cutting a round hole raises stress by a factor of three,” he says. “If the tanker designer did a good job, then a great deal of modification will be needed. Any sharp corners will also dissipate lots of energy.”

But there could be some alternative uses for the world’s discarded oil tankers. One New York-based artist recently proposed tipping a 300-metre-long supertanker on its end and anchoring it vertically in a harbour as a visual reminder of the need for mankind to end the fossil fuel era.

A group of Dutch architects have also proposed turning old supertankers into floating public villages that contain shopping malls, concert venues, museums, swimming pools and a public park on the top deck. But the firm behind the concept, Chris Collaris Design, say they have yet to find anyone brave enough to take the concept further.

But anchoring an oil tanker in such a way that it can be safely boarded and used by thousands of people is a tricky problem. Others believe it may be better to turn these enormous steel beasts into something that provides services to people rather than being somewhere they can meet and gather.

A Norwegian company called EnviroNor is developing technology it hopes can be used to convert oil tankers into mobile waste water treatment plants. These offshore treatment plants could then be sent to cities around the world that are struggling with water shortages. EnviroNor say a single tanker could treat the waste water from a city of 250,000 inhabitants. Mooring these converted tankers alongside wind farms, they could also use renewable energy to desalinate water for coastal cities.

Since 1985, 39 tankers of various sorts have been sunk off the coast of the US and one off the coast of Malta

But one of the most common current uses for old oil tankers after scrapping is perhaps also the most surprising – turning them into wildlife havens. Oil tankers are more commonly associated with harming marine life due to spills after accidents, but at least 40 of these vessels have been deliberately sunk to create artificial underwater reefs.

“If they are cleaned properly, oil tankers have a very big surface for things to attach to underwater and they will have a long lifespan,” says Dalia Conde, director of science at Species360, an international conservation research organisation, who recently created a global database of ships that have been deliberately wrecked to create artificial reefs. “There is the potential to attract a lot of fish, molluscs, different seaweeds.”

Cleaning up an oil tanker is an expensive business, though – it can cost several million dollars to mop up all the toxic mess that accumulates in these vessels. But since 1985, 39 tankers of various sorts have been sunk off the coast of the US and one off the coast of Malta. Unfortunately, little work has been done to monitor the impact these vessels have had on the ocean environments where they were sunk.

Anecdotal reports from divers who have visited some of these tankers, however, suggests they host a rich diversity of life including lobsters, shellfish, barracuda and sharks. The wreck of the supertanker MT Haven, which sank off the coast of Genoa, Italy after an explosion on board in 1991 has also become a popular diver site. Although 40,000 tons of oil poured into the sea in the accident, it has since become home to a wide array of marine animals.

“It is surprising that so many of these ships have been deliberately sunk to provide habitats for fish,” says Conde. “But we need to start monitoring these sites properly. With the crisis we are facing in our oceans and climate, it would be good if there was a way of using ships like oil tankers to do some good.” (BBC)

•Buildings in northern Syria and south-east Turkey were not capable of withstanding the two powerful earthquakes

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