A new idea on how Earth's outer shell first broke into tectonic plates
The activity of the solid Earth—for example, volcanoes in Java, earthquakes in Japan, etc.—is well understood within the context of the ~50-year-old theory of plate tectonics. This theory posits that Earth's outer shell (Earth's "lithosphere") is subdivided into plates that move relative to each other, concentrating most activity along the boundaries between plates. It may be surprising, then, that the scientific community has no firm concept on how plate tectonics got started. This month, a new answer has been put forward by Dr. Alexander Webb of the Division of Earth and Planetary Science & Laboratory for Space Research at the University of Hong Kong, in collaboration with an international team in a paper published in Nature Communications. Webb serves as corresponding author on the new work.