![]() The common point of the recent probabilistic seismic hazard assessment studies was that they have addressed the seismic hazard based on fault source modelling with characteristic recurrence through the commonly used Poissonian and/or more complicated renewal models (e.g., for Italy, for Marmara). Using time-dependent methods, the occurrence probability of large earthquakes (M >7.0) in the Marmara Sea was calculated to be around 40% for the next 30 years starting from the year 2004 by and the year 2016 by. In fact, many recent studies indicate the high probability of having an earthquake with magnitude up to 7.4 especially on the fault segments in the Marmara Sea, passing from about 20 km south of the city of Istanbul. As such, as new data and methods emerge, updates of seismic hazard models also become indispensable. Since the 1999 earthquakes, the mitigation of the seismic risk in the Marmara region and particularly in Istanbul has been a major aim and to this end several geological and seismological studies have been conducted for the characterization of seismic sources, especially within the Marmara Sea and for the identification of the associated earthquake potential that would enhance reliable estimations of the seismic hazard levels in the region. The two destructive earthquakes that occurred in the Eastern part of Marmara region at the closing of the 20th century, namely the August 17, 1999, M7.6 Izmit and November 12, 1999, M7.2 Düzce earthquakes, have been a turning point in the community perception of the high seismic risk prevailing in Marmara region, which hosts several highly populated cities, among them Istanbul with its 15 million population and contributing to more than 30% of Turkish GDP. ![]() The time-independent and time-dependent seismic hazard results in terms of spatial distributions of three ground-shaking intensity measures (peak ground acceleration, PGA, and 0.2 s and 1.0 s spectral accelerations (SA) on rock having 10% and 2% probabilities of exceedance in 50 years) as well as the corresponding hazard curves for selected cities are shown and compared with previous studies. Probabilistic seismic hazard assessment (PSHA) is conducted based on characteristic earthquake modelling for the fault segments capable of producing large earthquakes and smoothed seismicity modelling for the background smaller magnitude earthquake activity. A revised fault segmentation model, alternative earthquake rupture models under a Poisson and renewal assumptions, as well as recently derived global and regional ground motion prediction equations (GMPEs) are put together in the present model to assess the seismic hazard in the region. In this connection, the most recent findings and outputs of different national and international projects concerning seismicity and fault characterization in terms of geometric and kinematic properties are exploited in the present study to build an updated seismic hazard model. However, pressing too many times may cause a warning message to appear and result in a zero score for that clip.The increase in the wealth of information on the seismotectonic structure of the Marmara region after two devastating earthquakes ( M7.6 Izmit and M7.2 Duzce events) in the year 1999 opened the way for the reassessment of the probabilistic seismic hazard in the light of new datasets. ![]() You will not be penalised if you press on some of the potential hazards as well. Remember that you can press more than once or twice. You can practise these clips as many times as you need and master your skills of noticing developing hazards on time. This means that our clips are licensed by DVSA and are specifically designed to prepare you for the hazard perception part. On this website you can purchase full access to all hazard perception clips that DVSA has created for practising purposes. The recommended way to prepare for the Hazard Perception test part is to practise recognising developing hazards with the DVSA CGI revision clips. How to prepare for the hazard perception test? Hazard perception test for lorry, bus and coach drivers will contain 19 video clips with 20 developing hazards to be spotted. ![]() The pass mark for car and motorcycle hazard perception test is 44 out of 75 points. Depending on your ability to spot a developing hazard on time, you may score up to 5 points per hazard. This means that 13 video clips contain one developing hazard, while one clip contains two hazards. The Hazard perception test (for car and motorcycle drivers) consists of 14 video clips of typical road situations and features 15 developing hazards. ![]()
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