The change in Earth's moment of inertia, a quantity called J2 - dot, due to the ongoing isostatic rebound in Canada after the last ice age, has been well observed by satellite orbit monitoring, e.g., of the Lageos laser reflecting satellites.
«We have to account for the fact that the ocean basins are actually getting slightly bigger... water volume is expanding,» he said, a phenomenon they call glacial isostatic adjustment (GIA).