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91.
Tekkehamam geothermal field is located in the South of Menderes Graben (Aegean region) and is one of the most important geothermal sites of Western Anatolia. Umut geothermal field is a part of the Tekkehamam field. This study was conducted in order to determine the origin and hydrogeochemical properties of the geothermal waters. For this purpose, sampling was done in order to check the chemistry of the water, and 18O, 2H isotope analyses done at four wells, nine natural springs and three cold water sources. According to the results of the chemical analysis, the geothermal waters were determined to be of Na + K-SO4 type. Additionally, 14C and 3H analyses were done in selected well and spring waters for the purpose of age determination of groundwater; most of the waters were determined to be submodern. Geothermometer calculations show that the reservoir temperature for the Umut geothermal field ranges between 148 and 180 °C. Stable isotope results indicate that Umut geothermal waters are meteoric in origin. Mixing between shallow and deep waters is the dominant subsurface process that determines the physical and chemical character of the waters. 相似文献
92.
Hasan Hüseyin Aksu Mehmet Zakir Kanbur Muhittin Görmüş 《Arabian Journal of Geosciences》2017,10(17):387
A ground penetrating radar (GPR) survey was performed on the E?irdir Lake to obtain the structural properties of Kumdanl? and surrounding faults. GPR data was collected along ten profiles in various directions by using 100–200-MHz GPR antennas. The radar sections showed that the Kumdanl? Fault, SW-NE in direction, and also some other neighboring NW-SE normal faults have played an active role in forming the E?irdir-Hoyran Lakes. The deformation and the geometry obtained from the results show that the Kumdanl? Fault is a sinistral strike-slip fault including oblique and segmented displacements. The other faults (Kemerdam? and Akkeçili) have mainly normal fault systems. Their trends are generally NW-SE in direction. It is also observed that they are younger than the Kumdanl? Fault system. These fault properties demonstrate the E?irdir Lake side has an extensional structure trending SW-NE. 相似文献
93.
Evaluation of a recently proposed record selection and scaling procedure for low‐rise to mid‐rise reinforced concrete buildings and its use for probabilistic risk assessment studies
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This paper evaluates a recent record selection and scaling procedure of the authors that can determine the probabilistic structural response of buildings behaving either in the elastic or post‐elastic range. This feature marks a significant strength on the procedure as the probabilistic structural response distribution conveys important information on probability‐based damage assessment. The paper presents case studies that show the utilization of the proposed record selection and scaling procedure as a tool for the estimation of damage states and derivation of site‐specific and region‐specific fragility functions. The method can be used to describe exceedance probabilities of damage limits under a certain target hazard level with known annual exceedance rate (via probabilistic seismic hazard assessment). Thus, the resulting fragility models can relate the seismicity of the region (or a site) with the resulting building performance in a more accurate manner. Under this context, this simple and computationally efficient record selection and scaling procedure can be benefitted significantly by probability‐based risk assessment methods that have started to be considered as indispensable for developing robust earthquake loss models. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
94.
The aim of this study is to investigate the seismicity of Central Anatolia, within the area restricted to coordinates 30–35° longitude and 38–41° latitude, by determining the “a” and “b” parameters in a Gutenberg–Richter magnitude–frequency relationship using data from earthquakes of moment magnitude (Mw)?≥?4.0 that occurred between 1900 and 2010. Based on these parameters and a Poisson model, we aim to predict the probability of other earthquakes of different magnitudes and return periods (recurrence intervals). To achieve this, the study area is divided into six seismogenic zones, using spatial distributions of earthquakes greater than Mw?≥?4.0 with active faults. For each seismogenic zone, the a and b parameters in the Gutenberg–Richter magnitude–frequency relationship were calculated by the least squares method. The probability of occurrence and return periods of various magnitude earthquakes were calculated from these statistics using the Poisson method. 相似文献
95.
96.
Hasan Firat Pulat 《Marine Georesources & Geotechnology》2013,31(5):466-472
The present study examines the suction characteristics and swelling behavior of clayey soils when exposed to natural seawater with respect to distilled water. The effects of saline waters on the engineering behavior of soils need to be determined since the salinity of the pore fluid of soils near coastal areas increases continuously. Six clayey soil samples with different mineralogy and characteristics were gathered and tested to determine the suction and swelling characteristics in the presence of natural seawater and distilled water. The results show that the total suction values of the samples are higher in the presence of seawater than in distilled water. The samples with high swelling potential have lower matric suction values than nonswelling soils. Moreover, in contrast to swelling-type soils, the matric suction values of the nonswelling soils remain similar in the presence both distilled water and seawater. The modified free swell index (MFSI) of the samples is well correlated with the liquid limit (LL), plasticity index (PI), and cation exchange capacity (CEC) in distilled water. However, coefficients of determination decreased in the presence of seawater. Also, there is no significant correlation existing between total and matric suction values and the MFSI values of the samples. 相似文献
97.
While it is obvious that large-scale gravity studies should account for the sphericity of the Earth, each case should be examined.
If a geometry model is very large for the 3D-gravity calculation, it cannot be correctly defined in Cartesian coordinates.
Because of the Earth’s curvature it is necessary to use spherical coordinates, the importance of which is shown in this paper.
The calculation of the gravity for a cylinder reveals, 1 m above the center of the cylinder, a relative difference of 13%
between the models with Cartesian and spherical coordinates. 相似文献
98.
Mehmet Simav Hasan Yildiz Ali Türkezer Onur Lenk Emin ?zsoy 《Studia Geophysica et Geodaetica》2012,56(1):215-230
Sea level trends and interannual variability at Antalya and Menteş tide gauges are investigated during the 1985–2001 period,
quantifying the roles of atmospheric, steric and local land motion contributions. Tide gauge sea level measurements, temperature/salinity
climatologies and GPS data are used in the analyses and the results are compared with the output of a barotropic model forced
by atmospheric pressure and wind. The overall sea level trends at two tide gauges collocated with GPS are in the range of
5.5 to 7.9 mm/yr during the study period, but showing different behaviour in the sub-periods 1985–1993 and 1993–2001 due to
variations in the contributing factors both in space and time. After the removal of the atmospheric forcing and steric contribution
from sea level records, the resulting trends vary between 1.9 to 4.5 mm/yr in Antalya and −1.2 to −11.6 mm/yr in Menteş depending
on the period considered. Vertical land movement estimated from GPS data seems to explain the high positive residual trend
in Antalya during the whole period. On the other hand, the source of the highly negative sea level trend of about −14 mm/yr
in Menteş during 1985–1993 could not be resolved with the available datasets. Interannual variability of wind and atmospheric
pressure appear to dominate the sea level at both tide gauges during the study period. Atmospheric and steric contributions
together account for ∼50% of the total sea level variance at interannual time scales. Mass induced sea level variations which
were not considered in this study may help to close the sea level trend budgets as well as to better explain the interannual
sea level variance. 相似文献
99.
Hasan Yildiz 《Studia Geophysica et Geodaetica》2012,56(1):171-184
Gravity field and steady-state Ocean Circulation Explorer (GOCE) is the first satellite mission that observes gravity gradients
from the space, to be primarily used for the determination of high precision global gravity field models. However, the GOCE
gradients, having a dense data distribution, may potentially provide better predictions of the regional gravity field than
those obtained using a spherical harmonic Earth Geopotential Model (EGM). This is investigated in Auvergne test area using
Least Squares Collocation (LSC) with GOCE vertical gravity gradient anomalies (Tzz), removing the long wavelength part from EGM2008 and the short wavelength part by residual terrain modelling (RTM). The results
show that terrain effects on the vertical gravity gradient are significant at satellite altitude, reaching a level of 0.11
E?tv?s unit (E.U.) in the mountainous areas. Removing the RTM effects from GOCE Tzz leads to significant improvements on the LSC predictions of surface gravity anomalies and quasigeoid heights. Comparison
with ground truth data shows that using LSC surface free air gravity anomalies and quasi-geoid heights are recovered from
GOCE Tzz with standard deviations of 11 mGal and 18 cm, which is better than those obtained by using GOCE EGMs, demonstrating that
information beyond the maximal degree of the GOCE EGMs is present. Investigation of using covariance functions created separately
from GOCE Tzz and terrestrial free air gravity anomalies, suggests that both covariance functions give almost identical predictions. However,
using covariance function obtained from GOCE Tzz has the effect that the predicted formal average error estimates are considerably larger than the standard deviations of
predicted minus observed gravity anomalies. Therefore, GOCE Tzz should be used with caution to determine the covariance functions in areas where surface gravity anomalies are not available,
if error estimates are needed. 相似文献
100.
This study presents a ground-motion selection and scaling methodology that preserves the basic seismological features of the scaled records with reduced scatter in the nonlinear structural response. The methodology modifies each strong-motion recording with known fundamental seismological parameters using the estimations of ground-motion prediction equations for a given target hazard level. It provides robust estimations on target building response through scaled ground motions and calculates the dispersion about this target. This alternative procedure is not only useful for record scaling and selection but, upon its further refinement, can also be advantageous for the probabilistic methods that assess the engineering demand parameters for a given target hazard level. Case studies that compare the performance of the proposed procedure with some other record selection and scaling methods suggest its usefulness for building performance assessment and loss models. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献