And in last month’s diary scientific report, another team of researchers described how they used submarine cables to detect earthquakes off the coast of Chile, Greece and France. Well matched. Itzhak Lior, a seismologist at Israel’s Hebrew University and lead author of the paper, said, “While an earthquake is occurring, optical fibers are used to analyze the recorded signals in real time to estimate the magnitude of the earthquake. We can,” he said. “The game changer here is that along the fiber he can estimate the magnitude every 10 meters.”
Because traditional seismometers measure at a single point, localized data noise, such as that caused by large vehicles passing by, can cause deviations. “With fiber, it is actually very easy to distinguish between earthquakes and noise, because they are recorded almost instantly over hundreds of meters,” he says. “If it’s a local noise source like a car, train, etc., you can only see a few tens of meters.”
Essentially, DAS greatly improves the resolution of seismic data. It’s not meant to be a replacement for these highly accurate instruments, but rather a complement to them. “In that sense, it doesn’t matter if you have a seismometer or a DAS,” Lior says. “The closer you are to an earthquake, the better.”
There are also some challenges in DAS research that need to be addressed. In particular, fiber optic cables are not designed to detect seismic activity, they are designed to communicate information. “One of the problems with DAS cables, he said, is that they are not always ‘well coupled’ to the ground,” Park says. Detect rumbling. Scientists are studying how cable data collection changes depending on how the cable is laid underground. But with miles of fiber optic, especially in urban areas, scientists have many options. “It’s very dense, so you can handle a lot of data,” says Park.
According to Ariel Lellouch, a geophysicist who studies DAS at Tel Aviv University, another obstacle is that if you constantly shoot laser pulses down an optical fiber and analyze what comes back to your interrogator, you have a huge amount to analyze. information is created. “The sheer amount of data we get and the processing of it probably means we have to do a lot in the field,” he says. “That means you can’t afford to upload all your data to the internet and then process it in a centralized location. By the time you uploaded it, the earthquake would have gone far past you.”
In the future, that processing may actually take place in the interrogator itself, creating a network of continuously operating detectors. The same fiber optics that bring you the internet will bring you precious seconds of extra warning to prepare for earthquakes.
