I saw a video recently by a Professor Jerry Mitrovica in which he claimed that the gravitational effect of the Greenland and Antarctic ice sheets is so substantial as to 'raise' local sea levels. He suggests this is in the order of 100 meters for Greenland. See this video - around the 14 minute mark he claims that if the Greenland ice sheet were to suddenly melt, the sea level there would fall 100 meters. I get the idea from the video that this is a newly identified effect. This article 'seems' to validate that idea: http://www.livescience.com/15605-melting-glaciers-alter-earth-gravity.html The idea that Greenland has this effect on local sea level doesn't sound at all unreasonable to me, no different to underwater topology affecting the sea surface. However, in all my reading about the geoid and its relationship to MSL, I have never seen any reference to this effect. By geoid, I mean EGM96 which I *think* is the most current MSL approximating geoid. Bear in mind I am just a layperson with no expertise in this field, I am only reporting what I understand from what I've read. In reading about the geoid's surface shape and its relationship to the ellipsoid, generally the descriptions talk of the effect of gravity from the topology of the seafloor. As I understand it, the geoid and MSL are very close to each other, varying by no more than a meter or two. See this reference: https://www.wou.edu/las/physci/taylor/g492/geoid.pdf My question then is - if the gravitational effect of Greenland on local sea levels is in the order of 100 meters, AND this effect has only recently been identified (eg circa 2010 or so it seems), how is it that the geoid and MSL are so closely aligned if calculation of the geoid back in 1996 did NOT include this effect?