Canada has lower Gravity

If the Earth were perfect sphere, gravity would be the same around the sphere. But the Earth is not a perfect sphere. It's lumpy, mass is distributed unevenly both inside the Earth and on it's surface. Thus, gravity varies over different regions. So I think it's unusual but not impossible that Hudson Bay has lower gravity. Research say that: During the Ice Age, the two mile thick Laurentide Ice Sheet stretched from the arctic down through eastern Canada to the northern half of the Midwestern United States, spanning 5 million square miles. The massive sheet pressed down on the Earth deforming the crust somewhat like a Sumo wrestler on a trampoline surface. Even though the icy cover has all but vanished,the earth still feels the burden and like a slowly rebounding memory-foam pillow, it has yet to snap back to its ice free shape. The gravity measurements reveal that the slightly deformation could explain about 25 to 45 percent of the unusually low gravity that has persisted over a large section of Canada, probably over Hudson Bay.

I can't say I'm surprised. Similar thing with Germany and New Zealand where the gravity differs by something really small like .01 of a number.