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

HISTORICAL MATERIALS OF CHINESE EARTHQUAKESAND THEIR SEISMOLOGICAL ANALYSISYushou XieInstitute of Geophysics, State Seismological BureauChinaABSTRACTScience and culture developed early in China. Its seismicity is highand historical material is abundant. The earliest record goes back tothe 23rd century B.C. The Seismological Committee of Academia Sinicacompiled the Chronological Table of Chinese3 Earthquakes in 1956. In1978, we organized hundreds of seismologists, historians, archaeologists,archivists and librarians from various institutions and localities to reviseit. More than 20,000 varieties of literatures, documents and materials includingarchives written in ancient Tibetan and Manchurian, archives ofthe Republic of China, the Customs archives, rare books and local annals,peculiar literatures and stone inscriptions, abundant materials of macroseismicinvestigation, documents of neighbouring countries, bulletins ofglobal and regional networks of seismic stations and catalogues of earthquakeswere looked up. Through analysis and textural research, the falsewere eliminated and the true were retained. As a result, a series of fivevolumes of Compilation of Historical Materials of Chinese Earthquakesarranged chronologically from the 23rd century B.C. to 1980 A.D. totallingabout 5,000,000 Chinese characters was compiled. Two volumeswere published and the others will be published before the end of 1986.A catalogue of earthquakes from 1900 to 1980 with Ms 2 4.7 wasadded. The origin time and the location of focus were adjusted with computerwhenever possible. In order to unify the magnitude scale, Gutenbergand Richter formulas of 1945 and 1956 were used as standards forthe calculation of surface wave and body wave magnitudes respectively.Correlations of magnitudes listed in various catalogues relative to our revisedmagnitudes were obtained for regression purposes. For earthquakesof 1949-1980, the unification of magnitude scale was not well done, andwe are now revising them.The analysis of macroseismic materials of historical earthquakes is morecomplicated. The conversion of calendars and the identification of localitieshave been done by paleoastronomers and historical geographers respectively.For the estimation of magnitudes, regions with different ratesof intensity attenuation were delineated. We are now planning to getdifferent sets of emperical relations between instrumentally determinedmagnitude and macroseismic parameters, such as maximum intensity,isoseismal pattern, and extent of isoseismals with various intensities, forindividual regions from recent earthquakes with both instrumental andmacroseismic information. On this basis, we believe, the magnitude ofhistorical earthquakes can be better estimated.Historical Seismogramsand Earthquakes of the World162Copyright 0 I988 by Academic Press, Inc.All rights of reproduction in any form reserved.