Preliminary Results about the Catastrophic Earthquake of 7 September 1999 in Athens, Greece

Abstract

The catastrophic earthquake that hit the metropolitan area of Athens, Greece on 7 September, 1999 at 11:56:50.5 GMT has already been considered as the most important earthquake event in the modern history of Greece. In fact, it is the first moderate-to-strong shock ( Ms = 5.9) ever reported to have occurred at such a small epicentral distance (D ≈ 18 km) from the historical center of the city and the first shock in the long history of Athens to cause casualties within its urban area. About 100 buildings collapsed, causing 143 casualties, while another 800 were injured. Search and rescue operations were conducted in more than twenty-five different locations. Preliminary estimations indicate that the number of buildings classified as “red”, “ yellow”, and “green” after official inspection were 13,000, 62,000, and 110,000, respectively. “Red” indicates buildings either damaged beyond repair or heavily damaged but repairable; “yellow” indicates repairable, seriously damaged buildings; and “green” means not seriously damaged buildings. During the first days after the shock about 100,000 people were rendered homeless. More than 50 municipalities were affected, while the tangible loss caused is roughly estimated equal to about $3b U.S. From the point of view of economic loss it is the worst natural disaster reported in the modern history of Greece. First reports about the earthquake were published by Papadopoulos et al. (1999) and Pavlides et al. (1999, 2000), while Tselentis and Zahradnik (2000) prepared a preliminary report on the aftershock monitoring. Here we present more detailed though still preliminary results. In the remainder of this report the 7 September 1999 shock is referred to as “the Athens earthquake” for reasons of brevity. The basement rocks in the active region are Paleozoic shales and sandstones in altered phylites and quartz conglomerates, Triassic-Jurassic crystalline limestones, dolomites, and a few outcrops …