If a substantial amount of calcium is discovered, coronary artery disease may be likely. A CT coronary angiogram, in which you receive a contrast dye injected intravenously during a CT scan, also can generate images of your heart arteries.
At converging plate boundaries, two situations are possible. First, both volcanoes and earthquakes form where one plate sinks under the other. This process, called subduction, takes place because one plate is denser than the other. The denser plate, which invariably has oceanic crust on its top, does the sinking. Second, only earthquakes occur when two plates collide (obduct), building a mountain range.
Why and where do earthquakes occur? If we look at the pattern of where earthquakes occur around the world, it is clear that most of the earthquake activity is concentrated in a number of distinct earthquake belts. For instance, there are many earthquakes recorded around the edge of the Pacific Ocean, or in the middle of the Atlantic Ocean.