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

EVALUATION OF DAMAGE AND SOURCE PARAMETERSOF THE MALAGA EARTHQUAKE OF 9 OCTOBER 1680D. Murioz and A. UdiasCa'tedra de GeofisicaUniversidad Complutense de Madrid, Madrid, SpainABSTRACTOn the 9th of October 1680, an earthquake caused widespread destructionin the city of MBlaga and surrounding region in south Spain.A comprehensive search for contemporary documentation was made andthe information used for a detailed analysis of the damage and characteristicsof this earthquake. Intensities were evaluated at 38 localities and anisoseismal map has been drawn. Maximum intensity reached VIII-IX inthe MSK scale and covers an area of approximately 20 km radius towardthe west of MBlaga. Damage in the city of MQlaga has been studied in fulldetail, where about 20% of the buildings were totally destroyed and 60%suffered heavy damage, half of them had to be abandoned. Low quality ofconstruction contributed to the damage. Total number of casualties wasnot high, approximately 60 dead and 150 injured. Radius of perceptibilitywas fairly large, the shock was felt in Madrid 400 km away with intensityIV. Intensity attenuation and focal parameters have been derived from theintensity distribution. This study shows that contemporary documentsmust be studied with care in their historical and cultural background toavoid overrating in the evaluation of intensities.1. IntroductionOn the 9th of October 1680, an earthquake occurred in southern Spain producingheavy damage to the city of Mdaga and nearby towns and villages. This shock,one of the most important to occur in southern Spain since 1500, is listed in allSpanish catalogues (concerning catalogues of earthquakes in Spain, see Muiioz andUdias, 1982). However, oldest catalogues show some confusion regarding the date.Zahn (1696) and Moreira de Mendonsa (1758) date it in November, while Perrey(1847) and Mallet (1858) list three events in September 1679, August and October1680, which are obviously the same shock. In the recent catalogues, maximumintensity assigned to this shock is: Milne (1912) I1 (Milne scale), SAnchez Navarro-Neumann (1920) X (Forel-Mercalli scale), Munuera (1963) VIII (Mercalli scale) andIX (Fore1 Scale). The modern catalogue (Mezcua and Martinez Solares, 1983) givesthe following entry: 9 October 1680, 7h, 4' 24' W, 36' 30' N, I = IX (MSK scale),south of MQlaga. The epicenter is located offshore, but as will be shown, there isnot sufficient evidence for this.To understand the importance of this earthquake and the information containedin the contemporary documents, the historical and demographic situation of Spainand in particular of Andalucia must be taken into account (Ambraseys et al., 1984).The year of the earthquake, 1680, corresponds to the reign of Carlos I1 (1661-1700)who occupied the throne of Spain after the death of his father Felipe IV in 1665.Historical Seismogramsand Earthquakes of the World208Copyright 5 198h by Academic Press, Inc.All rights of reproduction in any form resened.