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:
Oceanic trenches, such as the Puerto Rico trench, are long, narrow topographic depressions of the seabed. The deepest parts of the ocean floor, they define one of the most important natural boundaries on the Earth's solid surface: the one between two lithospheric plates.ceanic trenches, such as the Puerto Rico trench, are long, narrow topographic depressions of the seabed. The deepest parts of the ocean floor, they define one of the most important natural boundaries on the Earth's solid surface: the one between two lithospheric plates.