Under the influence of gravity ice will flow or creep, albeit glacially. Stand in front of a glacier or the edge of an ice sheet and if you’re patient enough, you will see it creep, inexorably. It may take a while (days, months) but like I said, be patient. Bits of ice may fall off the front (calve) but that’s more the product of gravitational instability and weakness at the exposed ice edge. If it wasn’t for the propensity to flow there would be no glaciers, and ice sheets would stand still.
Antarctic ice shelves, those thick, floating wedges and platforms of ice, are a direct consequence of ice flow. One of them, Larsen C, has been in the news of late because a very large chunk (5800 sq. km), broke off and floated away as an iceberg; the inevitable comparisons have the new iceberg (imaginatively named A68) as twice the size of Luxembourg or about the size of Delaware. The Larsen C collapse took place in July 2017 during the polar winter, thus requiring thermal images; scientists had to wait for the summer sun to rise before getting a first-hand view of the new iceberg. Continue reading
