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t. e. Seismic intensity scales categorize the intensity or severity of ground shaking (quaking) at a given location, such as resulting from an earthquake. They are distinguished from seismic magnitude scales, which measure the magnitude or overall strength of an earthquake, which may, or perhaps may not, cause perceptible shaking.
AD 62 Pompeii earthquake. On 5 February AD 62, an earthquake of an estimated magnitude of between 5 and 6 and a maximum intensity of IX or X on the Mercalli scale struck the towns of Pompeii and Herculaneum, severely damaging them. The earthquake may have been a precursor to the eruption of Mount Vesuvius in AD 79, which destroyed the same two ...
v. t. e. The Modified Mercalli intensity scale (MM, MMI, or MCS) measures the effects of an earthquake at a given location. This is in contrast with the seismic magnitude usually reported for an earthquake. Magnitude scales measure the inherent force or strength of an earthquake – an event occurring at greater or lesser depth. (The " Mw ...
Richter established two features now common to all magnitude scales. First, the scale is logarithmic, so that each unit represents a ten-fold increase in the amplitude of the seismic waves. [ 12 ] As the energy of a wave is proportional to A 1.5 , where A denotes the amplitude, each unit of magnitude represents a 10 1.5 ≈32-fold increase in ...
Unlike the Richter and moment magnitude scales, it is not a measure of the total energy (magnitude, or size) of an earthquake, but rather of how much the earth shakes at a given geographic point. The Mercalli intensity scale uses personal reports and observations to measure earthquake intensity but PGA is measured by instruments, such as ...
11 October 1138. Magnitude. Mw 7.1 [ 1 ] Epicenter. 36°13′N37°10′E36.217°N 37.167°E. Casualties. 230,000 dead. The 1138 Aleppo earthquake was among the deadliest earthquakes in history. Its name was taken from the city of Aleppo, in northern Syria, where the most casualties were sustained.
The scale was first proposed by Sergei Medvedev , Wilhelm Sponheuer (East Germany), and Vít Kárník (Czechoslovakia) in 1964. It was based on the experiences being available in the early 1960s from the application of the Modified Mercalli intensity scale and the 1953 version of the Medvedev scale, known also as the GEOFIAN scale.
e. An interplate earthquake is an earthquake that occurs at the boundary between two tectonic plates. Earthquakes of this type account for more than 90 percent of the total seismic energy released around the world. [1] If one plate is trying to move past the other, they will be locked until sufficient stress builds up to cause the plates to ...