U. Ceken

The Engineering Strong‐Motion Database: A Platform to Access Pan‐European Accelerometric Data

This article describes the Engineering Strong‐Motion Database (ESM), developed in the framework of the European project Network of European Research Infrastructures for Earthquake Risk Assessment and Mitigation (NERA, see [Data and Resources][1]). ESM is specifically designed to provide end users only with quality‐checked, uniformly processed strong‐motion data and relevant parameters and has done so since 1969 in the Euro‐Mediterranean region. The database was designed for a large variety of stakeholders (expert seismologists, earthquake engineers, students, and professionals) with a user‐friendly and straightforward web interface. Users can access earthquake and station information and download waveforms of events with magnitude≥4.0 (unprocessed and processed acceleration, velocity, and displacement, and acceleration and displacement response spectra at 5% damping). Specific tools are also available to users to process strong‐motion data and select ground‐motion suites for code‐based seismic structural analyses. [1]: #sec-13

Tectonic Implications of Microseismic Activity and Fault Plane Solutions around Izmir City

Western Anatolia is one of the most seismically active and expeditiously extending regions in the world. The large-scale deformation in the Western Anatolia is dominated by the collision of the African and Arabian plates with Eurasia. This collision causes a westward migration of the Anatolian block from the east to the Aegean Sea in the west. Izmir city is the capital of Aegean region, and also 3rd biggest city of Turkey with its more than 4 millions inhabitants. This study aims to reveal present micro-seismic activity and seismotectonic features obtained from a local-scale accelerometric array.

WinFoc - A Windows-based Individual Focal Mechanisms Program

We present a software dealing with focal mechanisms solutions for educational and research purposes. It gives reasonable results by performing graphical interface of the beachball diagrams. Plots can facilitate to understand the kinematics of fault ruptures. The program is used to examine the nodal planes, calculate the orientation of the Strike, Dip and Rake, and to plot the possible structural model on the block diagram representing the beachball diagram. It is written in Visual Basic 6, and has all the advantages of the Windows OS.

Evaluation of Spectrum Behaviour on Acceleration and Displacement Records

This study aims; - Using the acceleration records as well as the displacement traces to determine the spectral source parameters described above by using P & S waves and noise records, - Showing the possibility of obtained the corner frequency (Fo) without converting acceleration traces into displacement, - Determining evidences of the parameter Fmax, and, - Comparing the spectrum characteristics obtained from noise, P and S waves both of acceleration and displacement data. Spectral seismograms of 10 earthquakes recorded by acceleration stations of IzmirNet, are presented, here, to discuss spectral behaviour of seismic signals included both acceleration and displacement records. Earthquake parameters of events are also given in the text.

Seismic studies from small aperture accelerometric network in Izmir metropolitan city, Turkey

This study deals with the results obtained from IzmirNet local strong-motion network installed in Izmir metropolitan city. Data were interpreted in terms of engineering seismology and earthquake engineering, correlation of noise using accelerometric array, seismological and seismotectonics studies. Site characteristics reveal an amplification factor equal or greater than 6.0 for a dominant frequency interval between 0.6-1.5 Hz on alluvial deposits observed mostly around the Izmir Gulf. Bigger frequencies and less amplifications were also detected for limestones and andesitic volcanic units. Recent study about cross-correlation of noise exposes underground velocity structure by using station-pairs methods. Low group velocities present at the east of the gulf where thick Quaternary-aged deposits exhibit over there. City was under high seismic risk according to the locations of recorded events by IzmirNet. Izmir, Orhanli-Tuzla and Seferihisar faults are candidate to produce a destructive earthquake in the future according to the present seismic activity and focal mechanisms solutions. Stress tensor study illuminates E-W aligned faulting under the N-S extension regime.