They don't deform easily; they tend to be more brittle.
它们不容易变形；它们是更脆的。
2
When the glacier comes into contact with bedrock walls or is otherwise under some kind of stress, but can't deform quickly enough.
当冰川与基岩壁接触，或者在其它方面受到某种压力，但变形速度不够快时。
3
If you leave, for example, a bar of ice supported only at one end, the end, the unsupported end will deform under its own weight, it'll kind of flatten out at one end, get distorted, deformed.