The Breakdown of Developing Democracies: The Cases of Turkey and Chile

Abstract not availabl

Site effect and its relationship to the intensity and damage observed in the June 27, 1998 Adana-Ceyhan earthquake

The site response at 15 stations in the Adana-Ceyhan region (Southern Turkey) is calculated from the recordings of aftershocks of June 27, 1998 Adana-Ceyhan earthquake (M-S=6.2) by using the Standard Spectral Ratio (SSR) and the Horizontal-to-Vertical Spectral Ratio (HVSR) methods. While the two methods are in good harmony at a few stations in determining the site effects, they show differences on the estimated amplifications or on the site resonance frequencies at most stations. It was not clear which one of the two methods underestimates or overestimates the amplification values. We observe that at some stations, where the local site conditions are rather complex, the vertical component records are strongly influenced from the local soil conditions. Thus, the HVSR method fails at these stations. The SSR method underestimates the amplifications at some stations since the rock site, selected as reference site, has its own site response and/or the path correction we applied, considering the geometrical spreading factor only, is insufficient. At the sites where high intensity values were observed, we found high amplifications. The fundamental soil frequencies characterize the damage properties observed in the Adana-Ceyhan earthquake. The fundamental soil frequency is nearly at 1.1 Hz at the Ceyhan site, where severe damage was observed in the 5-6 story buildings, while the fundamental soil frequency is between 3-6 Hz at the Adana site, where damage was in the low-story buildings. Therefore, in addition to inefficient construction practices, it is clear that the resonance effects have also contributed to the observed damage

Numerical 2D modeling of site response in Dinar Graben, Southwest Turkey, and comparison with observations

The October 1, 1995 Dinar earthquake (M-L=5.9) caused extensive damage within a limited area in Dinar town located in southwestern Turkey. Graben structure of the damaged area suggests the basin edge effects as a potential factor on the occurred damage. In this study numerical 2D site responses in the Dinar Graben are computed by using a finite-difference scheme and numerical results are compared with the observations within the graben. Our results suggest that the ground motions within the Dinar Graben were dominated by surface waves generated from the edges of the garben. In addition to magnifying amplitudes within the graben, the surface waves increased the duration of ground motion. Synthetic response spectra of the mainshock have shown that spectral accelerations at different sites in the graben are larger than the observed one. High spectral accelerations and long durations of ground motion may explain the extensive damage observed within the Dinar Graben

Imaging the basin and fault geometry from the multichannel seismic reflection data in the Tekirdag Basin, Marmara Sea, Turkey

Determination of the fault geometry in the Marmara Sea has been a major problem for the researchers after the occurrence of the 1999 August 17 Golcuk (M = 7.4) earthquake. To shed a light to the problem we applied the pre-stack Kirchhoff depth migration technique to the multichannel seismic reflection data of three profiles to investigate the basin and fault geometry in the Tekirdag Basin in the western Marmara Sea. The boundary of the basin and its sediments were revealed in N-S and NE-SW directions in depth sections. We identify major fault types involving these structures at different locations in Tekirdag Basin showing that the basin is developed under their movement. The North Anatolian Fault is imaged and interpreted as transtensional character at the centre of the Tekirdag Basin that is symmetrically divided with a large distributed zone. The fault plane is imaged through the depth of 2 km dipping to the north with 90 degrees in the upper 350 m and 82 degrees in the lower part. The basin thickness reaches about 2.5 km at that point. Syn-transform sediments of the basin are disturbed by some normal faults dipping to the north. These faults are represented by notable displacements of the reflections which prompted us to consider them as a potential tsunami source if they move during a large earthquake along the major fault. Another major fault is identified at the westernmost of the basin. Because it shows the same character as Ganos fault, it might be submarine part of it. It has reverse component with the dip angle of 65 degrees to the north and trending along the western flank of the basin. A reverse fault is identified appearing in low angle (similar to 20 degrees) surrounding the edge of the submarine slide at southwest of the basin. From its geometry it is interpreted as a local fault formed between two main faults. From the sketch of the basin and the fault geometry obtained from the images we suggest that the basin should be formed by a pull-apart system

Common surgical procedures in pilonidal sinus disease: A meta-analysis, merged data analysis, and comprehensive study on recurrence

Abstract We systematically searched available databases. We reviewed 6,143 studies published from 1833 to 2017. Reports in English, French, German, Italian, and Spanish were considered, as were publications in other languages if definitive treatment and recurrence at specific follow-up times were described in an English abstract. We assessed data in the manner of a meta-analysis of RCTs; further we assessed non-RCTs in the manner of a merged data analysis. In the RCT analysis including 11,730 patients, Limberg & Dufourmentel operations were associated with low recurrence of 0.6% (95%CI 0.3–0.9%) 12 months and 1.8% (95%CI 1.1–2.4%) respectively 24 months postoperatively. Analysing 89,583 patients from RCTs and non-RCTs, the Karydakis & Bascom approaches were associated with recurrence of only 0.2% (95%CI 0.1–0.3%) 12 months and 0.6% (95%CI 0.5–0.8%) 24 months postoperatively. Primary midline closure exhibited long-term recurrence up to 67.9% (95%CI 53.3–82.4%) 240 months post-surgery. For most procedures, only a few RCTs without long term follow up data exist, but substitute data from numerous non-RCTs are available. Recurrence in PSD is highly dependent on surgical procedure and by follow-up time; both must be considered when drawing conclusions regarding the efficacy of a procedure