The vast and extensive undersea cable network that spreads the Internet to the world can also be used to monitor seismic activity. In fact, one of these cables has already detected an earthquake, proving that the technology works.
Although the world’s seas and oceans are huge, worryingly, most of the underwater areas are still not actively monitored. There is still a huge shortage of regularly updated geophysical data, as only a few specialized sensors are available. But new technology could change that.
A recently published article reports that a new method transforms submarine telecommunications cables into an array of sensors. The team behind this innovation has proven that the technology can also detect earthquakes and other ordinary ocean activities such as waves and currents.
“The technique we offer has the potential to transform our Earth viewing capabilities. The seafloor could be equipped with thousands of [such] sensors without replacing the existing undersea telecommunications infrastructure.”
In these sentences, the team is talking about the sections of a submarine cable that are caused by amplifiers and repeaters. Almost all cables currently laid on the ocean floor have these means of ensuring that data streams have enough energy to traverse safely and reliably. These repeaters are located every 45 to 90 km along a cable. The team uses custom spacings between repeaters spanning the entire transatlantic link.
If the method is used or applied globally, it could enable us to have thousands of permanent real-time environmental sensors on the ocean floor using pre-existing hardware. Combining the new method with pre-existing seismometer-based networks will greatly expand the global earthquake monitoring infrastructure.
Perhaps the most interesting feature of this innovation is that it does not require any changes or additions to the underwater infrastructure. The need for no additions or modifications makes the solution extremely cost-effective, scalable and quickly deployable.
The team also appears confident that they can expand their technology to monitor and understand other natural phenomena such as deep water flows, long-term seafloor temperature changes. Such uses seem possible, thanks to the high sensitivity of fiber optic cables.
Scientists are always fighting a losing battle against the huge upfront investment required to deploy climate-monitoring sensors. But this innovation could easily contribute to creating long-term and accurate climate models at well below the usual costs…