Answer : Slow.
Explanation : The rate at which glacial erosion occurs is very very slow, it is difficult to observe a glacier erosion. As there are two main processes which occurs in glacial erosion. Plucking which is defined as the erosion stage and which transports large chunks of rocks. As a glacier moves slowly over the landscape, the water melts below the glacier and seeps into cracks within the underlying bedrock. The glacial flows over certain surface of land and picks up the rocks in this process of getting eroded.