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.
Quick Answer. Most earthquakes occur along the boundaries between the Earth's tectonic plates. The crust of the Earth is divided into plates. When a plate collides with or slides past another plate, this causes earthquakes. For example, as the Pacific plate moves past the North American plate, many earthquakes occur along the coast of California.