How do glaciers affect earths surface?

Answer 1

When they slide or move across the land they pick up rocks and soil which changes the Ground beneath it.

By glacial erosion which is when slowly over time large U shaped valleys are carved out; or by 'plucking' which is when rocks or boulders are literally plucked up from the surface and carried down the valley.
Rocks frozen underneath glaciers carve the land when glaciers move

Answer 2

because they carve things in the earths surface

Answer 3

Glaciers move slowly across the earth's surface, moving land and sediments. The land is moved, which effects the earth's surface.