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.
Earthquakes are measured using seismometers. Earthquakes often occur in volcanic regions due to the flow of magma in volcanoes and are an early warning of volcanic eruptions. Geologists rate earthquakes based on their magnitude, which is the amount of energy released during the quake.