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181.
Serap Kahraman Türkay Baran İ. Aydin Saatçi Müjgan Şalk 《Pure and Applied Geophysics》2008,165(2):331-347
A probabilistic seismic hazard analysis (PSHA) for Western Anatolia is presented using the Gutenberg-Richter (G-R) frequency-magnitude
relation. Since the modeling is sensitive to the location of seismotectonics boundaries, to use the information content of
the observed earthquake data, as a general rule the borders of the affected area are extended. In this study, the effect of
the region’s definition on the G-R model is debated on the Western Anatolian region, which is one of the most seismically
active and rapidly deforming regions of the world throughout the ages. Calculations are carried out for two subregions and
one combined region as a whole using the seismic catalog from 1900 to 2005. The data sets are determined by the region’s borders
with the parameters computed according to these data sets by the least-squares and maximum likelihood methods, and then future
predictions are estimated via these parameters. Comparing the results with historical earthquake records, most appropriate
regional borders for Western Anatolia are defined, and for this new region G-R model parameters are obtained. 相似文献
182.
183.
In earthquake prediction studies, the regional behaviour of accurate 222Rn measurements at a set of sites plays a significant role. Here, measurements are obtained using active and passive radon detector systems in an earthquake-active region of Turkey. Two new methods are proposed to explain the spatial behaviours and the statistical uncertainties in the 222Rn emission measurements along fault lines in relation to earthquake occurrence. The absolute point cumulative semivariogram (APCSV) and perturbation method (PM) help to depict the spatial distribution patterns of 222Rn in addition to the joint effects of the K dr, the radon distribution coefficient, and the perturbation radon distribution coefficient (PRDC). The K dr coefficient assists in identifying the spatial distributional behaviour in 222Rn concentrations and their migration along the Earth’s surface layers. The PRDC considers not only the arithmetic averages but also the variances (or standard deviations) and the correlation coefficients, in addition to the size of the error among the 222Rn measurements. The applications of these methodologies are performed for 13,000 222Rn measurements that are deemed to be sufficient for the characterization of tectonics in the Keban Reservoir along the East Anatolian Fault System (EAFS) in Turkey. The results are evaluated for the ?çme earthquake (M L 5.4, 5.7 km, 23 June 2011), which occurred in the vicinity of the EAFS. 相似文献
184.
Can Zulfikar Mustafa Erdik Erdal Safak Hikmet Biyikoglu Cagatay Kariptas 《Bulletin of Earthquake Engineering》2016,14(9):2565-2578
This paper describes a rapid response and risk mitigation system Istanbul Natural Gas Distribution Network Seismic Risk Reduction Project (IGRAS) for the Istanbul Natural Gas Network (IGDA?). Upon the trigger signal received from the earthquake early warning system in Istanbul, the real-time algorithm at IGRAS system district regulators checks the threshold levels of ground-motion parameters and interrupts the gas flow if any exceedance is detected. Then the system: (1) produces almost real-time earthquake hazard maps by using on-line strong-motion data from the strong-motion network in Istanbul: (2) estimates the distribution of damage to the natural gas network; and (3) transfers these damage distribution maps to stakeholders to enable dispatching rapid response teams to high damage areas. 相似文献
185.
For centuries, inhabitants of coastal areas have suffered from the effects of tsunamis. Turkey, with a coastline of 8333 km, has experienced many tsunamis.Historical records reveal that, during the observation period over 3000 years, the coastal and surrounding areas of Turkey have been affected by more than ninety tsunamis. These tended to cluster around the Marmara Sea, the city of Istanbul and the gulfs of Izmit, Izmir, Fethiye and Iskenderun. Each of the tsunami occurrences surveyed in this paper deserves further individual study. The most extensive available information concerns the tsunamis associated with the Istanbul Earthquakes of 1509 and 1894, the Eastern Marmara Earthquake in 1963 and that of Izmit in 1999,which disturbed the Marmara Sea; the Earthquake of 1939 in Erzincan ineastern Anatolia; and the 1968 Bartn Earthquake, which affected Fatsa and Amasra on the Black Sea. In addition to these, it is known that a tsunami occurred in 1598 on the shores of the Black Sea in connection with an earthquake at Amasya in northern Anatolia. 相似文献
186.
Landfill site selection by using geographic information systems 总被引:3,自引:3,他引:3
One of the serious and growing potential problems in most large urban areas is the shortage of land for waste disposal. Although
there are some efforts to reduce and recover the waste, disposal in landfills is still the most common method for waste destination.
An inappropriate landfill site may have negative environmental, economic and ecological impacts. Therefore, it should be selected
carefully by considering both regulations and constraints on other sources. In this study, candidate sites for an appropriate
landfill area in the vicinity of Ankara are determined by using the integration of geographic information systems and multicriteria
decision analysis (MCDA). For this purpose, 16 input map layers including topography, settlements (urban centers and villages),
roads (Highway E90 and village roads), railways, airport, wetlands, infrastructures (pipelines and power lines), slope, geology,
land use, floodplains, aquifers and surface water are prepared and two different MCDA methods (simple additive weighting and
analytic hierarchy process) are implemented to a geographical information system. Comparison of the maps produced by these
two different methods shows that both methods yield conformable results. Field checks also confirm that the candidate sites
agree well with the selected criteria. 相似文献
187.
FERHAT OZCEP SAVAŞ KARABULUT OGUZ ÖZEL TAZEGUL OZCEP NAZIRE İMRE HALIL ZARIF 《Journal of Earth System Science》2014,123(1):73-89
Yalova City (Turkey) is in a tectonically active location that is particularly affected by the northern branch of the North Anatolian Fault Zone. Magnitudes 7.4 and 7.2 earthquakes in 1999 caused great destruction in Yalova. The heavy damage to buildings and other civil engineering structures was mainly due to liquefaction-induced settlement and site effects such as resonance and amplification. In the first phase of this study, the soil liquefaction potential index (PL) and the induced soil settlement were estimated. In the second phase, the effects on sites in Yalova soil were investigated using microtremor and earthquake data. The fundamental periods and amplification in soft soil were compared with microtremor data and strong ground motion records obtained by a local array of eight accelerograph stations deployed in Yalova. Thirty-seven ‘single site’ ambient noise measurements were taken in a dense grid of points covering the centre of the city. A comparison between fundamental periods obtained from strong ground motion records and from microtremor measurements showed similarities, in the 0.1–5 Hz range. Finally, soil liquefaction and amplification (or resonance) were divided into regions according to the extent of damage and the geotechnical/geophysical results. 相似文献
188.
İbrahim Uysal A. Dündar Şen E. Yalçın Ersoy Yildirim Dilek Samet Saka Federica Zaccarini Monica Escayola Orhan Karslı 《Mineralogy and Petrology》2014,108(1):49-69
We present the whole-rock and the mineral chemical data for upper mantle peridotites from the Harmanc?k region in NW Turkey and discuss their petrogenetic–tectonic origin. These peridotites are part of a Tethyan ophiolite belt occurring along the ?zmir-Ankara-Ercincan suture zone in northern Turkey, and include depleted lherzolites and refractory harzburgites. The Al2O3 contents in orthopyroxene and clinopyroxene from the depleted lherzolite are high, and the Cr-number in the coexisting spinel is low falling within the abyssal field. However, the orthopyroxene and clinopyroxene in the harzburgites have lower Al2O3 contents for a given Cr-number of spinel, and plot within the lower end of the abyssal field. The whole-rock geochemical and the mineral chemistry data imply that the Harmanc?k peridotites formed by different degrees of partial melting (~%10–27) of the mantle. The depleted lherzolite samples have higher MREE and HREE abundances than the harzburgitic peridotites, showing convex-downward patterns. These peridotites represent up to ~16 % melting residue that formed during the initial seafloor spreading stage of the Northern Neotethys. On the other hand, the more refractory harzburgites represent residues after ~4–11 % hydrous partial melting of the previously depleted MOR mantle, which was metasomatized by slab-derived fluids during the early stages of subduction. The Harmanc?k peridotites, hence, represent the fragments of upper mantle rocks that formed during different stages of the tectonic evolution of the Tethyan oceanic lithosphere in Northern Neotethys. We infer that the multi-stage melting history of the Harmanc?k peridotites reflect the geochemically heterogeneous character of the Tethyan oceanic lithosphere currently exposed along the ?zmir-Ankara-Erzincan suture zone. 相似文献
189.
190.
Zekai Şen 《Arabian Journal of Geosciences》2014,7(4):1627-1636
Previous studies lack proper and quick assessment of sediment yield rates in arid regions. Sediment yield at a point along the main channel of a drainage basin is an integrated result of upland, gully, and channel erosion, transportation, and depositional processes. The external dynamic agents of sediment yield are water, wind, gravity, temperature change, ice, and biological activities. Although each may be important in arid regions, at locations, occasionally present-day hydrological cycle works water are the most widespread agent of erosion and account for the bulk of sediment yield. This paper focuses on sediment yield formulations in arid regions in terms of little morphology in addition to the runoff discharge after a storm rainfall. Among the morphological variables are the drainage basin area, main channel slope, and the drainage density. Hence, the channel head is represented by the combination of drainage area and the slope. The emphasis is given to the determination of simple and straightforward sediment yield rate formulations by dimensional analysis technique. Three simple formulations are derived, and two of them are applied to one of the largest wadis, Wadi Baysh, with its 54 sub-basins, in the southwestern Saudi Arabia. 相似文献