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

fIistorica1 Seismicity and Earthquuke Catalogues for Indian Region 339sources. Besides updating tlie list of earthquakes to 1975, lie also pointed out someinconsistencies in tlie dates and places of some earthquakes given by Gubin (1968).He lias also expressed some doubt about the 2G ,May 1618 earthquake near Bombaywhich could possibly be due to a hurricane rather than an earthquake. However, tliiscatalogue does not extend to earthquakes of I < V which is important for delineatingshear zones or other tectonic regions, particularly in lesser seismically-active areassuch as peninsular India. Also, there are some omissions in the catalogue preparedby Cliandra (1977), even for earthquakes of I 2 V. For example, an earthquakeof i%f = 5 wliicli occurred on April 9, 1909 (Tandon and Srivastava, 1974) has notbeen reported in this catalogue.Recently, tlie Iiiclian Society of Earthquake Teclinology lias published an earthquakecatalogue compiled by Bapat, Kulkarni and Guha (1983) of Central Waterand Power Research Institute, Pune, for tlie region bounded by Latitude 0 - 50” Narid Longitude 50 - 100” E from the historical times to 1979. The catalogue givesan exhaustive bibliography for the years 1763 to 1979. The catalogue contains afew ancient earthquakes such as: Karaclii earthquake of 326 B.C., based on sealevel changes; Kalibagan earthquake of 1730 zk 100 B.C. in Rajastlian, from archaeologicalevidence of ruins; Braliminabad earthquake of 8th century B.C., basedon archaeological ruins; arid an earthquake in 56 B.C. in the Vindyan mountains.There are only 86 events reported from the 26th century B.C. to 1800 A.D. To quotetlie authors: “certainly Lhere were other major eartliquskes during long ancient andhistorical period in the area but no different evidences could be traced which wouldidentify the events to be tectonic origin like earthquakes”.The catalogue by Bapat et al. (1983) also has the following limitations: (1)different magnitudes reported in the literature have not been standardized; and (2)from the year 1965, the epicentres have been taken from the U.S. Geological Surveyinstead of the ISC Bulletins whicli are based on more voluminous worldwide data.After tlie occurrence of the 1967 Koyna earthquake, a project was undertaken byIMD to prepare a detailed catalogue of earthquakes for peninsular India based onthree newspapers] Hindu, Times of India, arid Stateman, published from Madras,Bombay, and Calcutta respectively. Of these, Times of India is the oldest. Earthquakesreported through these newspapers froin the time of publication of the veryfirst issues were noted until 1072 (Srivastava and Ramaclia1iclran, 1985). This cataloguehas brought out some interesting features about the seismicity of peninsularIndia as noticed from tlie list of locally-felt earthquakes up to 1900 (Appendix). Inthis list, the intensity of earthquakes are assigned on the basis of the newspaper descriptions.This catalogue after scrutiny is being brought up-to-date so that shocksof smaller intensity which have significance for seismicity and risk analysis studiesmay be assigned due weiglitage. As many shocks in the new catalogue have beenfelt over a siuall area, their intensities were sniall. Significant errors in assigningtheir locations (epicentres) are not expected. Keeping this in view, assignment ofgeographical coordinates to the epicentres will enable us to utilize the data directlyt hrougli tlie computer.It may be of interest to point out tlie significance of the new catalogue for peninsularIndia, where small events have been reported several years prior to significantearthquakes. For example, near Jabalpur where an earthquake of I = VI occurredon 17 May 1903 (Turner et al., 1912), a felt earthquake has been reported on25 November 18G8. In the region of a damaging earthquake on 8 February 1900