Lot of silt in that water! There has been some interesting debate recently on the efficacy of glacial erosion under the Greenland ice sheet -- and more broadly whether or not global average erosion rate has increased due to northern hemisphere glaciation over the past few million years. One recent estimate [1] suggests:
> We find that, although runoff from Greenland represents only 1.1% of the Earth’s freshwater flux, the Greenland ice sheet produces approximately 8% of the modern fluvial export of suspended sediment to the global ocean.