Quantum Entanglement Sensors: Revolutionizing Earthquake Detection , One of the scariest things about an earthquake is not how much damage it causes, but when and where it will strike next. The beginning of 2023 has already brought significant earthquake activity, with February earthquakes in Turkey and Syria killed tens of thousands of people.
Many experts predict that this type of destructive earthquake activity will only continue, threatening others risk areas all over the globe.
Although the scientists cannot predict when an earthquake might occur, many develop sensitive devices that could improve earthquake detection. One such device is quantum sensor.
By suspending atoms at ultra-low temperatures (near 0 degrees Kelvin) in laser arrays, quantum sensors can detect minute changes in gravitational waves, while becoming even more sensitive when quantum entangled.
Although this setup offers more in-depth data to improve earthquake models, it can be expensive.
How to measure an earthquake
Current detection methods use a network of seismographs all over the globe. At any node in the network, any earthquake or even a rock slide can trigger a seismograph measurement.
“Current systems are made up of accelerometers [seismographs] which detect the earliest arriving seismic waves, which are pressure waves [p-waves] which move the ground but are not as destructive as subsequent shear waves [s-waves] which travel more slowly,” says Daniel Bodis, a professor at the University of Birmingham, who holds a Ph.D. in civil engineering.
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The limitations of seismographs
While these measurements can help triangulate the epicenter of an earthquake, they have significant limitations. “It’s some warning, but it means [seismographs] they can’t produce warnings of critical events because they only see something when the ground starts shaking,” adds Bodis.
In other words, seismographs can only measure waves like earthquake occurs, forcing scientists to race against time to warn the risk areas before it is too late.
With quantum sensors, increasing the sensitivity to gravitational waves can lead to more data before earthquake, giving valuable time to issue a warning.
Quantum entanglement
By combining groups of atoms and a network of lasers, scientists can observe fluctuations in individual atoms in this network, resulting in large amounts of precise data.
Scientists are working on adding quantum entanglement to these sensors where two particles in the apparatus will be entangled or have interdependent quantum states. When this happens, the atoms are less susceptible to environmental noise, giving more precise readings of gravitational wave fluctuations.
Although entangled quantum sensors may not suffer from the problems of traditional seismographs, such as signal jamming, they do have their problems, mainly the fragility of the entire system.
Quantum entanglement is incredibly fragile and can break quickly. This makes the implementation and maintenance of such a system difficult and expensive. But research is underway to make these systems more stable, especially to create other devices such as quantum computers.
Improving earthquake detection
Boddice is one of many researchers looking into using these quantum devices for an improved earthquake detection system.
“By adding a network of gravimetric sensors for constant monitoring, if you detect a mass shift caused by the movement of the plate on multiple detectors at the same time, you will get an earlier warning,” says Bodis. This can be confirmed once the accelerometers start detecting incoming waves as the gravitational signal travels at the speed of light.
Combining quantum sensors with traditional seismographs could provide more precise data for researchers to use in earthquake modelsleading to better hotspot forecasts and more effective warning systems.
Advantages of quantum sensors
The sensitivity gained through this kind of quantum sensing “has the potential to save thousands of lives by providing the critical extra seconds needed to reach safer locations at the onset of an earthquake,” says Anjul Loiacono, vice president of Quantum Signal Processing at Infleqtion (formerly ColdQuanta), a quantum computing company developing quantum sensors to detect gravitational waves.
Although the warning window may be extended only slightly, Boddice believes that this extra time can still make a difference in reducing deaths during an earthquake.
“For example, if a rail under a train bends while the train is moving, it will crash; so it is better to stop the train to avoid this impact,” he says. “You can take action to avoid putting people in more risky places.”
This can refer to operating elevators or closing tunnel entrances where people can become trapped when an earthquake strikes. You can also turn off the power and gas mains to avoid fires in the event of a rupture during an earthquake.
“Individually these actions may seem like small things, but cumulatively for a large enough earthquake they can make a significant difference in casualties,” adds Bodis.
Limitations of earthquake predictions
While these devices can improve alert times, they can also be too sensitive, which poses other challenges.
“The high sensitivity of quantum gravimeters is both a blessing and a curse,” says Bodis.
This is because all kinds of forces, such as the movement of vehicles, send vibrations through the Earth that can register in these sensitive devices. This challenges the work of discerning the background noise from important but small gravitational signals.
As a result, some scientists are turning to machine learning algorithms. This technology can help interpret what is noise and what is an earthquake.
“Combining the power of machine learning with quantum gravity sensing technology will lead to faster and more accurate detection of upcoming earthquakes,” says Loiacono.
Machine learning algorithms can also help predict trends in future earthquake activity.
Are earthquakes more common today?
Current data shows significantly spike in the number of major earthquakes in the last two years and experts predict that this trend will continue.
However, this increasing trend is largely due to the fact that detection capabilities have increased, as well as vigilance to report and impact earthquakes in more populated and developed areas.
“There’s a long history of detecting earthquakes, and they’re no more common now than they were in the past,” says Bodis. “I suspect the combination of more populated areas increases the chances of them being seen or more reported because of the 24-hour news.”
He suggests that an objective, comprehensive and long-term look at the trend would actually reveal that they are no more common now than at any other time.
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