See the North

In September 2017, I stepped out of a Zodiac into ankle-­deep salt water, gravel rasping at its rubberized hull. I set an anchor into the beached pack ice and turned to offer my arm to the ten passengers who had endured the wind and waves that dogged our passage through the Foulk Fjord, in northern Greenland. Red-­faced, clutching cameras and iPads, they made their way to some higher ground beyond the shoreline. Having seen them safely to dry land, I stripped off my Gore‑Tex outer layers, activated my GPS watch, and began to run.

Like many runners, I am fastidious when it comes to data. I have never seen the satellites that communicate, second by second, with the device on my wrist, but I trust that they are there, tracking me with geospatial precision. What I like most about GPS data is that it cannot be faked: You either ran a route, or you didn’t. You either achieved a certain pace, or you fell short. As your watch collects the satellite pings...