1433 Bulletin of the Seismological Society of America, 91, 6, pp. 1433–1445, December 2001 Analysis of Accelerations from the 1 October 1995 Dinar, Turkey, Earthquake by John G. Anderson, Yuehua Zeng, and Haluk Sucuoglu Abstract The Dinar earthquake, 1 October 1995, occurred in southwestern Turkey and had a moment magnitude of 6.4 and a normal faulting mechanism. The earth- quake caused 90 deaths, over 200 injuries, and a large amount of damage. It was recorded by seven strong-motion accelerographs. The strong-motion accelerograph at Dinar is on the edge of the surface projection of the fault. The record from Dinar is possibly unique in its proximity to the causative fault for this type of mechanism. The Dinar strong-motion station is in a small, stiff building on soft sediments with a shallow water table. The peak acceleration was 0.32g on the horizontal component perpendicular to the fault trace. The earthquake was caused by rupture on the Dinar fault, which is a normal fault trending generally toward the south-southeast, with the hanging wall on the west. There was surface rupture along about a 12-km segment of this fault. The Dinar strong-motion station is at the south end of the fault, under 1 km from the nearest surface trace. The hypocenter was at the south end, beneath Dinar, with rupture propagating toward the north and away from the strong-motion site. A specific composite source model was found that reproduces the statistical characteristics of the ground motions and also approximately reproduces the low- frequency waveform in the strong motion. In this model the fault length, L, is 12.5 km, the width, W, is 17.3 km, and the moment M 0 is 4.72  10 25 dyne cm. The fault strikes 130° and dips 45° toward the southwest, from the surface to 12 km. For the composite parameters, the largest subevent (R max ) is 4.0 km, the rupture velocity is 1.5 km/sec, and the subevent stress drop is 60 bars. After Anderson (1997) the composite source model parameters imply that the static stress drop was 36 bars, the radiated seismic energy in this event was 4.3  10 21 ergs, the apparent stress was 18 bars, and the Savage-Wood ratio was 1.0. Most of the seismic energy is released at depths greater than 2 km. The major asperity is beneath the location where syn- thetic aperture radar interferometry found the maximum surface deformation. Introduction The Dinar earthquake, 1 October 1995, in southwestern Turkey (Fig. 1) is significant for several reasons. The earth- quake caused 90 deaths, over 200 injuries, and a large amount of damage. The recovery effort involved retrofitting a large number of damaged structures, and these retrofits have been subsequently tested by some moderately strong shaking (Wasti and Sucuoglu, 1999). From the viewpoint of strong-motion seismology, of the seven strong-motion ac- celerographs that recorded the earthquake (including four stations within 100 km, shown in Fig. 2), the one from Dinar is over the surface projection of the fault, making it one of the nearest records of a normal-faulting earthquake. This ar- ticle describes the strong-motion data from the Dinar earth- quake, evaluates site effects, and develops a source model for the earthquake. Dinar Earthquake The Dinar earthquake occurred at 15 hr 57 min UTC on 1 October 1995. Figure 1 is a map of the eastern Mediter- ranean region that shows the general location of Dinar. Table 1 summarizes the source parameters for this event, as pro- vided by several agencies. Based on teleseismic analysis, the seismic moment is between 1.7  10 25 and 4.7  10 25 dyne cm, which corresponds to a moment magnitude between 6.1 and 6.4. We use the moment from the Harvard catalog, giv- ing M w 6.4, for comparison with other earthquakes using the most standard methodology. The Dinar earthquake took place in a tectonic setting that is fairly complex. Kocyigit (1984) and Reilinger et al. (1997) interpreted it as being near the intersection of the