How to Detect a Crevasse on a Glacier?

https://outdoorsfaqs.com/how-to-detect-a-crevasse-on-a-glacier/
Signs of crevasses in a glacier covered with snow are areas with sagging and unusual depression, and also with slightly different snow color. It is usually easier to detect such places from a distance than when you are already on a glacier with crevasses. But crevasses are not always observable, bear this in mind.