Final answer:
Dr. Moore can explain that the continents are moving closer due to tectonic plates shifting. This process, known as plate tectonics and initially proposed by Alfred Wegener as continental drift, happens as Earth's crust moves over the mantle.
Step-by-step explanation:
Dr. Moore could explain to the concerned students that the continents are moving closer together due to the shifting of tectonic plates. This concept, known as plate tectonics, was first comprehensively presented by Alfred Wegener when he proposed the theory of continental drift in the early 20th century. Wegener's idea, which initially lacked a mechanism and faced skepticism, eventually gained acceptance as further evidence supported the movements of Earth's solid crust over its molten mantle.
Wegener's hypothesis was strengthened by the discovery of identical fossils on continents separated by oceans and the congruence in the shapes of coastlines, like those of South America and Africa. These observations suggested that the continents were once joined in a supercontinent called Pangaea. Over millions of years, the drifting apart of these landmasses has shaped the current configuration of our planet's crust, leading to the observation from GPS data that two continents are converging in Dr. Moore's study.
It's important to clarify that the ocean between these continents is not causing them to move closer but rather the movement is an effect of the dynamic nature of Earth's lithosphere, which is divided into plates that move slowly but continuously over geological time.
Learn more about Plate Tectonics