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Location and Magnitude of Earthquakes

The graphs below (Figs 1-3) illustrate the flow of data processing using the Atlas with typical screen shots, showing the stages through which the data of a local earthquake are reduced from the recorded seismic data up to the final estimate of the earthquake parameters. The print screens below are for a minor earthquake with a magnitude of 2.43 on the Richter scale, which took place on May 6, 2010 at coordinates 24.89oN and 37.33oE and at a depth of 1.3 km. It occurred near the Red Sea coast, about 110 km northwest of Yanbu and southwest of the Harrat Al-Shaqa (Lunayyir).

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The use of the length of the seismicity signal as highlighted in the red area.

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Wave graphs from 3 seismograph stations and a recording are shown on a wide-scale time schedule in the upper part of screen.

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The recognition of seismic events resulting from human activities, i.e., usually explosions, such as rock or building explosions from quarrying or demolision. It is possible to determine the type of such events from their depths and locations or through wave and spectral analyses of the recorded data. The differences lie in the frequencies between the natural and anthropogenic sources. The above graph shows a model of the spectral shapes (power against frequency) that was recorded by four seismographs.