Fiber Optic Cables Can Spy on Nature’s Noisy Inhabitants
A Newfangled Technique
One of the world’s most peculiar test beds stretches above Princeton, New Jersey. It’s a fiber optic cable strung between three utility poles that then runs underground before feeding into an “interrogator.” This device fires a laser through the cable and analyzes the light that bounces back. It can pick up tiny perturbations in that light caused by seismic activity or even loud sounds, like from a passing ambulance. It’s a newfangled technique known as distributed acoustic sensing, or DAS.
The Noisy Nature of DAS
DAS can track seismicity, monitor earthquakes, and volcanic activity. However, scientists recently stumbled upon a rather noisier use of the technology. In the spring of 2021, Sarper Ozharar, a physicist at NEC Laboratories, noticed a strange signal in the DAS data. “We realized there were some weird things happening,” says Ozharar. “There was a distinct frequency buzzing everywhere.”
The team suspected the “something” wasn’t a rumbling volcano but the cacophony of the giant swarm of cicadas that had just emerged from underground, a population known as Brood X.
The Science of Cicada Monitoring
A colleague suggested reaching out to Jessica Ware, an entomologist and cicada expert at the American Museum of Natural History, to confirm it. “So when Sarper and the team showed that you could actually hear the volume of the cicadas, and it kind of matched their patterns, I was really excited,” says Ware. Thanks to some specialized anatomy, cicadas are the loudest insects on the planet, but all sorts of other six-legged species make a lot of noise, like crickets and grasshoppers. With fiber optic cables, entomologists might have stumbled upon a powerful new way to cheaply and constantly listen in on species.
DAS, a Tool for Remote Sensing
DAS is all about vibrations, whether they be the sounds of a singing brood of cicadas or the shifting of a geologic fault. Fiber optic cables transmit information, like high-speed internet, by firing pulses of light. Scientists can use an interrogator device to shine a laser down a cable and then analyze the tiny amounts of light that bounce back to the source. Because the speed of light is a known constant, they can pinpoint where along the cable a given disturbance happens.
Impact on Insect Monitoring
“Part of the challenge that we face in a time when there’s insect decline is that we still need to collect data about what population sizes are, and what insects are where,” says Ware. “Once we are able to familiarize ourselves with what’s possible with this type of remote sensing, I think we can be really creative.” Add insects to the quickly growing list of things DAS can spy on. This discovery could prove to be a game-changer for entomologists and scientists, providing a new way to monitor insect populations.
I have been a full-time professional writer for over 10 years, and have written for some of the biggest publications in the world. My work revolves around cryptocurrencies and blockchain technology, and I am widely considered to be one of the leading experts in these fields.I have written two books on the subject matter, and my articles have been featured in major news outlets such as The Wall Street Journal, Forbes, and Huffington Post. In addition to writing, I also give talks and seminars on cryptocurrency investing, and am a regular commentator on CNBC, Bloomberg, and other financial news networks.
