Two independent sets of geophysical data are shown to be particularly sensitive to the thickness of the continental lithosphere. Both are connected with the response of the planet to the last deglaciation event of the current ice age. The first set of data consists of relative sea level histories in the age range 0--10 kyr B.P. from sites along the eastern seaboard of North America. Such data appear to require a continental lithospheric thickness in excess of 200 km. The second set of data consists of the ILS record of the motion of the rotation pole over the time range 0--75 years B.P., which reveals a secular drift at the rate of 0.95 (¿0.15) deg/106 years toward Hudson Bay. When the viscosity profile of the mantle is fixed to that required to explain free air gravity and relative sea level data from within the ice margin and the observed nontidal acceleration of planetary rotation, then these observations also suggest a continental lithospheric thickness of the same order.