THE WORLD’S LARGEST EARTHQUAKES IN 1999

Abstract

Every year the Earth is shaken by several hundred thousand earthquakes with magnitudes of over 2.0 (1), mostly originating at the geotectonic plate boundaries. Two well-defined seismic belts, the circum-Pacific and the Mediterranean-Himalayan belts, are subject to the most frequent earthquake shocks. The latter also includes the region of Slovenia. Most earthquakes are weak and do not cause any material damage and do not claim human lives. In addition to these, there are several earthquakes which result in extreme destruction and even death. In 1999 there were 76 earthquakes that either reached a moment magnitude of Mw ≥ 6.5 or more, caused major material damage, or claimed human lives; 23 of them are mentioned in the text. The most devastating earthquake in 1999 occured on 17 August in Turkey, where approximately 17,840 people were killed. The 20 September Taiwan earthquake ranks first in terms of released energy, with a moment magnitude of Mw = 7.7 (2100 people were killed). The deepest earthquake occured on 8 April on the Russia-northeast China border, whose hypocentre was approximately 570 km below the surface. In 1999, earthquakes claimed almost 25,000 human lives (official toll). If all the missing persons are included in this figure, the toll rises to more than 40,000.