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

Helwan Historical Seismograms 475Although seismic recording in Helwan began in 1899, seismograms are availableonly from 1907 to the present. Phase readings from seismograms are available inmonthly bulletins, and a yearly seismological bulletin officially began in 1936. Adetailed report on near and local earthquakes recorded by the Helwan station from1903 to 1950 was published by Ismail in 1960.In July 1984, a microfilm camera and 20 rolls of film were provided to the Helwanstation through the IASPEI/UNESCO workshop on historical seismograms. Whenreceived, the Inter/COM Microfilm Recorder was installed and inspected by a Belland Howell representative in Egypt, who provided the necessary training to a technicianhired specifically for the microfilming operation. However, to proceed with theseismogram copying, the representative suggested that a microfilm reader-processorbe provided. The Helwan Institute has no budget to do this at present.Seismograms covering 5 years of data have now been copied, processed by theBell and Howell representative, and found to be acceptable. In addition, it hasbeen decided to copy all smoked paper seismograms and also to make arrangementsfor copying the photographic paper records. Because the Bell and Howell office inEgypt is a sales office only and does not process microfilm, we cannot be certain thatall seismograms are copied properly. In this regard, a reader-processor is necessary.Planned Studies(1) Because the seismographs that operated at Helwan from 1899 to the presenthave different natural periods, a study of the spectral magnitude of local and regionalearthquakes, is planned.(2) International cooperation is invited to reevaluate the magnitudes of local,near and distant earthquakes for hazards studies.REFERENCESIsmail, A. (1960). Near and local earthquakes of Helwan (1903-1950), Bulletin of HelwanObservatory, No. 49.Simpson, D. W., R. M. Kebeasy, C. Nicholson, M. Maamoun, R. N. H. Albert, E. M.Ibrahim, A. Meghed, A. Gharib, and A. Hussein (1984). Aswan Telemetered seismographnetwork, Proceedings of the third annual meeting of the Egyptian GeophysicalSociety.