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 boundary volcanism. Volcanic activity occurs at two types of plate boundaries: mid-ocean ridges and subduction zones. At mid-ocean ridges, basaltic eruptions produce new sea-floor crust. These underwater eruptions don't produce big mountainous volcanoes, which is why they are often overlooked as the most volcanically active features on Earth.