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.
Image credit: NASA. The two main answers to âhow earthquakes happenâ is: as a result of tectonic plates colliding and volcanic eruption. The shock waves associated with nuclear weapons testing and other man-made explosions. To be considered an earthquake a shock wave has to be of natural origin.Earthquakes Caused By Tectonic Plates: The theory of plate tectonics explains how the crust of the Earth is made of several plates, large areas of crust which float on the Mantle.Since these plates are free to slowly move, they can either drift towards each other, away from each other or slide past each other.Many earthquakes happen in areas where plates collide or slide past each other. The Elastic Rebound Theory applies to these quakes.ince these plates are free to slowly move, they can either drift towards each other, away from each other or slide past each other. Many earthquakes happen in areas where plates collide or slide past each other. The Elastic Rebound Theory applies to these quakes.