AHEAD European Archive of Historical EArthquake DataEuropean Archive of Historical EArthquake Data

Within the module NA4: "A Distributed Archive of Historical Earthquake Data" (coordinator of the module Dr. M. Stucchi) of the EU-NERIES project, the "Macroseismic Database of the Southern Balkan area" was compiled on a joint effort of ITSAK (Ch. A. Papaioannou and A.S. Savvaidis), as module Partner, and the Geophysical Laboratory of the University of Thessaloniki (B.C. Papazachos, as principal researcher, and C.B. Papazachos) for the time period 1000-1999. The database is temporarily hosted by the INGV-MI.

The source of the data (macroseismic Intensity Data Points) are:

• for the historical (before 1900) earthquakes, the books of Papazachos and Papazachou (1989, 1997, 2003) and
• for the earthquakes of the instrumental era, the bulletins of the National Observatory, the books of Papazachos and Papazachou (1989, 1997, 2003) and individual studies.

This paper draws on previously unpublished historical documents, supplemented by the re-examination of published but not readily accessible sources, to investigate the seismicity of the Eastern Mediterranean region during the period 1690 to 1710. It aims in particular at the study of a number of important but little-known earthquakes in the region. Individual events are discussed in chronological order, and their location is indicated on the map (fig. 1).

In order both to gain an understanding of the tectonics of an area and for seismic hazard evaluation, it is important to extend our knowledge about the earthquakes which occurred there as far back in time as possible. Further to these objectives, the results of such research are of value to historians, both architectural, and social and economic.

The short rime-period and wide area covered in the present study were selected with the aims of (a) achieving as complete a retrieval of information as possible around the time and location of the larger earthquakes under investigation, (b) demonstrating the importance of utilising information derived from disparate sources, and indicating the extent to which documents in different languages complement each other, and (c) showing how much new information about the seismicity of the region can be found, even for this short period of observation of two decades. The reasons for choosing such a large area are, first, that we need to be aware of the full extent of earthquake activity during the period of our observations - we must look, therefore, not only for near, destructive shocks but also beyond the immediate vicinity of an affected area for large earthquakes that could have easily caused damage at large epicentral distances. Secondly, we must assess how adequate our sources of information are, that is whether they provide us with information continuously, or only at certain periods. The extent to which these aims have been realised may be partially judged on the basis of the case histories given below. Wider conclusions concerning both the relative copiousness of the historical sources available for this period, when considered in the context of those available for other periods, as well as the significance of the period 1690-1710 in the seismological history of the area, must await further research.

At present very little is known in any detail about the seismicity of the Eastern Mediterranean region during this relatively late period of its history. Of the 65 events identified in this paper, only a small fraction are listed in earthquake catalogues and for most of these the information given is fragmentary and incomplete. For instance, almost nothing is known about the seismic activity of the region of Negreponte (Chalkis), northeast of Athens, a region associated with active tectonics today. Similarly obscure are the facts about the earthquake known to have occurred in Athens around this time, the only earthquake alleged to have caused damage to the city during its long history. Nothing is known about the earthquake of 1705 in the Bekaa valley in Lebanon, the site of earlier and later destructive earthquakes (AMBRASEYS; AMBRASEYS- MELVILLE; AMBRASEYS-BARAZANGI). While the newly-discovered documents from the Ottoman Archives presented here greatly enhance our understanding of many events during the time- period under consideration, it is in these three cases, in particular, that their value becomes apparent. Previous studies of the seismicity of the Eastern Mediterranean which ignored such documents were thus bound to be deficient in their interpretation of the earthquakes that occurred in the area.