Question #3e948

1 Answer
Nov 17, 2017

It depends on which plate, plates, and what period of time is being referenced.

Explanation:

Presently it is estimated that the Atlantic Ocean is spreading about 1cm a year while the Pacific Ocean is moving about 4 cm a year.

The original theory of Plate Tectonic Continental Drift postulated rapid movement. The movement of the plates in the past very well might have been much more rapid than the presently observed rates.

The Pacific Plate moved. more than 10 feet in 1906 in a manner of mins.in the famous San Francisco Earthquake. There is a beach on the top of a 1000 foot cliff in Oregon. It is possible that the Beach was pushed up from sea level to its present elevation in a single movement of the plates.

At the end of the time of the dinosaurs there were many more volcanos than are observed in the present. Volcanos are the result of plate movements. The plates may have been moving much more rapidly than in the present. The change of the climate due to the volcanic ash is one theory as the the extinction of the dinosaurs.

The present rate of plate movements overall is less than 5 cm per year or about 2 inches per year. This rate may not have always been the same.