News of what fiber optics provides just keeps getting better

I think we can all agree that fiber optics is an amazing transport medium. It’s more durable than coax or copper wire, has a much longer use life, and can reliably deliver data at crazy fast speeds. But, get this, now seismologists—the scientists that measure earthquakes–are relying on fiber optics to predict them.

We’re sitting on millions of miles of dark fiber and research scientists from UC Berkeley and the Lawrence Berkeley National Lab opined that there may be a way to use it to predict earthquakes more accurately than traditional seismometers. Actually, they got the idea from the oil & gas industry, whose engineers needed to measure underground movement related to pipelines and oil wells. They decided fiber optic cables might work; they did, and are currently being used today.

To detect earthquakes, seismologists use seismometers to detect tremors above ground. While they work well, they’re limited by the number of sensors that feed them information. The more sensors, the better results, and at least 3 are required to detect an earthquake’s epicenter. Why don’t they just drop a lot of sensors, you ask? Well, here’s the rub—they’re extremely pricey. They do work well, but, along with being expensive, they aren’t the easiest thing to manage and monitor. They pull in a lot of data caused by ambient conditions, such as traffic, construction, etc. And, before seismologists can get to the good, usable earthquake-related information, the other stuff has to be sifted through. Expensive, tedious, and time-consuming doesn’t sit well with scientists.

Here’s how it works. When light is pulsated down fiber optics, any movement in the fiber caused by, for example, an earthquake, creates reflection and dispersion, which scatters the light. The resolution was unprecedented and provided dense data points. According to a scientist who worked on the project, it’s like having a worldwide siesmological network.

For 6 months, the researchers used a laser interferometer to measure this movement on a 13,000-mile stretch of dark fiber from a test bed owned by The Department of Energy. Just 3 months into the test period, they recorded—prior to it happening—what was to become Mexico’s strongest earthquake of the last century.

They’re now ready to test it on transoceanic fiber optic cabling dropped on the ocean’s sea floor.