One of the buzziest technologies in modern science may be running right under your feet. Fiber optic cables bring you the internet as data-rich pulses of light, but they also detect signals from the surrounding environment: Researchers can analyze the light that’s scattered when a volcanic eruption or tsunami jostles the wiring. Known as distributed acoustic sensing, or DAS, the technique is so sensitive that it can track your footsteps as you walk over a cable , and may one day even warn you of an impending earthquake .

Now, researchers have laid a fiber optic cable on the seafloor near a glacier in Greenland, revealing in unprecedented detail what happens during a calving event, when chunks of ice drop into the ocean. That, in turn, could help solve a long-standing conundrum and b

See Full Page