Summarization of the paper.
Added on - 25 Sep 2019
Summarization of the paperSeismograms are used to produce the basic quantitative information about the seismic source andthe interior of the earth. By usingseismographic instruments we can get wide dynamic range ofseismograms with quality frequency band.seismographic instrumentsconsists of a massattached to a fixed base. When earth quake occurs base will be move and the mass does not, itremains the same position. The motion of the base with respect to the mass is commonlytransformed into an electrical voltage.Seismograms analysis used to find the Earth's interior andphysics of earthquakes ,by improving magnitude quantity and quality. In the last 80 years about10 earthquakes are occurred larger than surface wave magnitude (Ms)7 in the world.Global seismicityFrom the table of values given in the paper It is clear that the values of Ms is most significant todiscuss about global seismicity. From those tables we can understand that global seismic activityis non uniform with respect to time. Because of these factors we need a data of seismicity over along period of time is most important.The magnitude and frequency relation of earth quakes areanalyzed over different years.Thurst mechanism is applied to analyse the most of the large earth quakes in the subductionzones. very large false event occurrences also notable.The sanriku earthquake 1933 andSumbawa earthquake 1977 is examples of false event occurrences. false event defines the failurewith in oceanic plate whereas thurst event defines the slip between the plate boundaries.earthquake potential of seismic graphs are evaluated using thurst events and normal failure events.Rupture process of large earthquakesRupture process is also a one of the important research subject to find out the large earth quakesin the instrumental seismology.Long period sesimograms of large subduction zone earthquakesto study the regional variations of the nature of subduction zones.In 1906 rupture process isinvestigated in san Francisco earthquake by boore using ewing seismographs.From the arrivaltime of P and S waves and their amplitudes at Mt.hamilton with in 35 km of the san Andreasfault.