When walking on Hofsjökull glacier in Iceland, I wondered: how do people camp on multi-day trekking trips across icecaps, such as when crossing Greenland? My primary choice of tightening a tent is to put pins into the soil; this doesn't work on ice. My second choice is to use rocks to fasten my guy lines; this doesn't work either on an ice cap. How would I fasten my tent? And not to forget, it can be very windy on those ice caps and glaciers, as there are no obstacles.
You don't use ordinary tent pegs, you use something a lot more substantial. For example, pictured below are two ice screws (cheap ones I found a picture of on Ali Express), which would work if the ice is hard enough. These screw into the ice and the threads hold them in place.
If you use these, and you leave your tent behind during the day, make sure you cover them with a pile of snow so they don't warm up in the sun, melt the ice, and pull out.