I showed up to the interview dressed to the nines, post double shot latte, and mentally prepped only to be ushered to a hallway lined with chairs and a dozen other potential applicants already waiting their turn. I knew I needed something to make me stand out if I had any chance of securing the job.
Answer 1: At plate boundaries where sea-floor spreading occurs, magma wells up to fill the space created by the plates that are moving apart. Check out this United States Geologic Survey (USGS) educational animation to see visually how it works:
plate boundaries new oceanic lithosphere is created in the gaps from upwelling magma from the mantle. This upwelling magma forms mid-ocean ridges, long mountain chains that mark the boundaries between diverging plates. The static size of the Earth implies that crust must be destroyed at about the same rate it is being created. Plate