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The intensity of local ground-shaking depends on several factors besides the magnitude of the earthquake, [3] one of the most important being soil conditions. For instance, thick layers of soft soil (such as fill) can amplify seismic waves, often at a considerable distance from the source, while sedimentary basins will often resonate ...
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.
Intensity data is collected from 4,300 observation stations equipped with "Model 95" accelerometers that measure strong ground motion [3] [4]. The agency provides the public with real-time reports through the media and Internet [5] giving event time, epicenter (location), magnitude, and depth followed by intensity readings at affected localities.
For example, a magnitude 7.0 quake in Salta, Argentina, in 2011, that was 576.8 km deep, had a maximum felt intensity of V, [19] while a magnitude 2.2 event in Barrow in Furness, England, in 1865, about 1 km deep, had a maximum felt intensity of VIII. [20] The small table is a rough guide to the degrees of the MMI scale.
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 ...
Thus, a magnitude zero microearthquake has a seismic moment of approximately 1.1 × 10 9 N⋅m, while the Great Chilean earthquake of 1960, with an estimated moment magnitude of 9.4–9.6, had a seismic moment between 1.4 × 10 23 N⋅m and 2.8 × 10 23 N⋅m. Seismic moment magnitude (M wg or Das Magnitude Scale ) and moment magnitude (M w) scales
For electron beams, intensity is the probability of electrons reaching some particular position on a detector (e.g. a charge-coupled device [2]) which is used to produce images that are interpreted in terms of both microstructure of inorganic or biological materials, as well as atomic scale structure. [3]
Radiant intensity is used to characterize the emission of radiation by an antenna: [2], = (), where E e is the irradiance of the antenna;; r is the distance from the antenna.; Unlike power density, radiant intensity does not depend on distance: because radiant intensity is defined as the power through a solid angle, the decreasing power density over distance due to the inverse-square law is ...