Historical Seismograms - Evidence from the AD 2000 Izu Islands ...

110 D. M. McGregor, A. A. Hughes, and R. D. Adamsadditional information such as: associated phenomena (e.g. tsunami, volcanism);flags indicating that the event was felt, damaging etc.; intensity data; magnitudedata; number of recording stations; type of event, (e.g. explosion, rock-burst etc.);and comments - any length of text may be added. This format is designed to holdthe maximum possible information, without taking up storage space unnecessarilywith null information.4 .S. Ret rie ual of InformationISC provides a consulting service for those with scientific or commercial need forlistings from this file. Events can be selected from the file by any combination orcriteria relating to time, location, depth, magnitude, intensity, or locating agency.Composite estimates can also be provided, which combine origin parameters fromprime estimates with magnitude determinations from other agencies.In addition to giving a listing of events, a line printer plot can also be generated,showing the positions of events superimposed on a representation of coastlines. Theearthquakes are represented by a figure which gives the magnitude of the largestevent reported at each position. Where no magnitude is assigned, events are shownby an asterisk. Underlining of a symbol indicates multiple events at the sameposition. Another option lists estimates of expected ground acceleration and feltintensity at a specified location for each event for which a magnitude is given.The information can also be reproduced on magnetic tape, in two formats, oneof which contains all the information on the file for the chosen events, but needssome simple programming to interpret, and another which contains only the basicinformation in fixed fields in 80-column card images.5. Station BulletinsMost data arrive at ISC in machine-readable form; on magnetic tape, on punchedcards, or by telex. Some readings come entered on special coding sheets for keyingat the Centre, but in addition many agencies and stations send bulletins, which arestored at ISC after their data have been extracted and used. Many of the mostvaluable contributions to ISC analysis come in this form, with information fromstations that are either remote, or in regions of high activity, or both.Naturally, the bulletins are more complete for the later years, but there are alsosome more important early collections. Among these are a set from Hungary withsome readings from Budapest for 1896, and more complete readings from 1905. By1909 this network comprised seven stations. Other early bulletins are for:V’ ienna 1905- 1907Hamburg 1912, 1913Strasbourg 1913, 1915-20, from 1934Tokyo 1922Soviet Union (8 stations) 1926, 1927, from 1930Kew1927 onwardsRiverview1927 onwardsCopenhagen1931 onwardsLa Paz, Bolivia1931 onwardsNanking from 1932Ksara, Lebanon from 1934These bulletins are available for study or copying.