Abstract

A very important geophysical contribution to appreciating modern tectonic theory has been the completion of seafloor magnetic mapping, plus radiometric and paleontological age dating of seafloor crusts beneath all Earth's oceans. This seafloor mapping places finite spatial and temporal constraints on the crustal plate motion history within all of the ocean basins, back to the Early Jurassic Period (approximately 170 million years ago). The magnetic patterns and age dating determined during this seafloor mapping program were historically interpreted as evidence for seafloor growth and spreading, which led to the promotion of Plate Tectonic theory during the 1960s ? a theory that adopts and continues to insist on the fundamental premise that Earth radius remains constant with time. In contrast, by removing this premise and allowing Earth radius to vary with time, this same seafloor mapping provides us with a unique opportunity to accurately measure past Earth radius, to both latitudinally and longitudinally constrain plate assemblages on smaller radius Earth models, and to quantify a rate of increase in crustal surface area, and hence radius throughout Earth history; giving rise to the alternative tectonic theory called Global Expansion Tectonics. Mathematical modeling of this seafloor mapping shows that Earth radius is increasing exponentially through time, and radius is currently increasing at a rate of 22 millimetres per year. While this seafloor mapping quantifies Global Expansion Tectonics as a viable alternative to conventional tectonic theory, a fundamental challenge is presented to physics, whereby an explanation is required to explain how and where additional matter is generated and accumulated within the Earth in order to comply with the increase in Earth radius, as evidenced from empirical seafloor crustal data.