Look under the surface of Cross Sound, south of Glacier Bay National Park, and you’ll find Facebook. Google is there, too, as is the picture of the cat you just posted on Instagram.
They all live side-by-side in a handful of hair-thin strands of fiber optic cable that run from Juneau to an anonymous point deep beneath the surface of the Gulf of Alaska. There, the cable joins another, slightly bigger cable that snakes north and south to Whitter and Oregon. Others run in parallel, linking Southcentral Alaska to the Lower 48.