
Black arrows: Spatially averaged horizontal velocities calculated using
a nearest neighbor scheme with a search radius of 800 km. The dashed
circle has a radius of 2100 km and is centered on the postglacial
rebound uplift (star). A solid circle with a 800 km radius is shown
to illustrate the search radius dimension.
Background: Interpolated vertical velocities. Only sites with randomwalk noise
magnitude < 1 mm/sqrt{yr}, category A sites, and sites with velocity standard
deviation less than 1.5 mm/yr are used. The interpolation scheme uses an
adjustable tension continuous curvature surface gridding algorithm
with a tension factor of 0.9.
