How fast a valley glacier gives up ground, and what it leaves behind on the slopes above it.

Where water goes when the ground has no streams, and which hollows are still moving.

A fixed set of cross-sections, measured the same way every three months, until the trend is plain.

Wet ground that moves slowly: tracking the water table against the surface that rides on it.

Channels that are dry for years, mapped for the one day they are not.

A railway on an old river terrace, and the bank that is quietly being cut away below it.