Glacier winds from advancing glaciers slow the growth of trees in their vicinity. This is evident even in the ring pattern of trees several hundred meters away from the glacier. Growth may stop at the foot but continue in the crown. Surges are not clearly reflected. Advancing ice may block drainage channels in the forefield and cause flooding. If this happens slowly and persists, the ring patterns reflect disturbances such as growth reduction or compression wood. Some of the trees may die. Sudden flooding by a surge may kill a whole stand rapidly.