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.
Where do most earthquakes occur? Earthquakes occur when the Earth's plates move and rub against or bump into each other. Quakes occur most frequently along the edges of plates, but they are also common along faults, which can be far from the edge of a plate. Faults are cracks where smaller sections of the plate move against each other.