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

184 N. N. Ambraseys and C. P. MelvilleMany of these issues are relevant to the identification and analysis of a largeearthquake that occurred in the Eastern Mediterranean on 20 May 1202.3. Previous CataloguesEarly catalogues either ignore the 1202 earthquake (Coronelli, 1693; Seyfart,1756; Dressdnischer, 1756; Berryat, 1761; Huot, 1837) or mention an earthquake on30 May 1202 (perhaps converting to the New Style calendar), which caused greatdamage to the Christian-held territory of Tyre, Tripoli, ’Arqa and Acre (Manetti,1457; Batman, 1581; Beuther, 1601). None of these authors quote their source ofinformation.Among later authors, Hoff (1840) quotes early editions of Muslim writers (Abu’l-Faraj, Abu ’1-Fida and Hajji Khalifa), all secondary sources, but separates theevents into two distinct earthquakes in 1201 and 1204. Hoff is followed by Mallet(1852, p. 30), who notes however that non-Arab authors have 13th, 20th or 30thMay 1202, probably referring to the sources cited by Perrey (1850, p. 18). Perreyquotes Baronius’s Annalium Ecclesiasticorum, where an account similar to that ofRobert of Auxerre’s, but dated 30 May 1202, is found (ed. 0. Raynaldo, Rome1646, xiii, 89); also Ralph of Coggeshall and Robert of Auxerre’s accounts (ed.Dom Bouquet, Rec. des Hist. de Gaule et de la France, xviii, 97, 265-6)’ cf. below.The chronicle published in L. Muratori, Rerum Italicarum Scriptores, XXVI, 85 isprobably Sozomenus’s 15th century universal history. The chronicle published inLuc d’Achery, Spicilegium, xi, 478 has not yet been examined. One or other ofthese latter two must give the date 13 May 1202. This results in three earthquakes,occurring in 1201 or 1202,20 May 1202 (Old Style) and 1204, which affected parts ofSyria, Mesopotamia and Egypt, though Perrey notes that the first two are probablythe same.Authors since Mallet add nothing but further chronological confusion, which inturn obscures the size and effects of the earthquake. Willis (1928), on the authorityof secondary works (Tholozan, 1879; Arvanitakis, 1903; Blankenhorn, 1905;Vigouroux, 1912) increases the number of earthquakes in the period to four, i.e. in1201, 1202, 1203, and 1204, and adds another two shocks in 597 and 600 A.D., whichare in fact the Muslim years covering the period 1201-1204 that he misinterpretsfrom Sprenger (1843), cf. Ambraseys (1962). Ambraseys’ own early work (196l),which is an uncritical translation of one of the many manuscripts of al-Suyuti’s treatise,passes on the errors in the text. Ambraseys’ studies on the seismicity of Iranand adjacent regions (1968, 1974) are very incomplete and occasionally misleading,but likewise continue to be used uncritically. Willis is followed by later authors,such as Sieberg (1932a,b), Kallner-Amiran (1951), Plassard and Kagoj (1968) andothers. Some produce two major earthquakes out of the 20 May 1202 event (Ben-Menahem, 1979), others five (Alsinawi and Ghalib, 1975), with an average of threedestructive shocks given by Poirier and Taher (1980), the only 20th century authorswho have the credit of using an extensive number of Arabic sources.4. Sources of Information.Owing to the Crusader presence in the Levant, information on the effects ofthe earthquake is available from both Christian and Muslim authors. Both sets ofdata naturally refer most particularly to the territory belonging to the respective