The full sequence of expansion to the present 12,800 km diameter, with the surface magnetic field, volcanic activity and plate boundaries indicated, shows how the movement of the original shields relates to the shock waves of the original impact - beginning in Central America directly opposite the original point of entry, the Himalyas, and resulting in the spreading of the Pacific Ocean, pushed out by the convection currents initiated by the path of the object.

The entire pattern of the tectonic activity of the planet's surface and the earthquake waves of its interior are a reflection of this original event.

It is also important to note that this expansion / contraction model also concurs with the basic ages of the areas of the crust, as determined by radioactive dating. ( Click here for: illustration of the ages of the seabeds )