Hydrochemical,isotopic, and reservoir characterization of the Pasinler (Erzurum) geothermal field,eastern Turkey

The reservoir temperature and conceptual model of the Pasinler geothermal area, which is one of the most important geothermal areas in Eastern Anatolia, are determined by considering its hydrogeochemical and isotope properties. The geothermal waters have a temperature of 51 °C in the geothermal wells and are of Na–Cl–HCO₃ type. The isotope contents of geothermal waters indicate that they are of meteoric origin and that they recharge on higher elevations than cold waters. The geothermal waters are of immature water class and their reservoir temperatures are calculated as 122–155 °C, and their cold water mixture rate is calculated as 32%. According to the δ¹³C_VPDB values, the carbon in the geothermal waters originated from the dissolved carbon in the groundwaters and mantle-based CO₂ gases. According to the δ³⁴S_CDT values, the sources of sulfur in the geothermal waters are volcanic sulfur, oil and coal, and limestones. The sources of the major ions (Na⁺, Ca²⁺, Mg²⁺, Cl^?, and HCO₃ ^?) in the geothermal waters are ion exchange and plagioclase and silicate weathering. It is determined that the volcanic rocks in the area have effects on the water chemistry and elements like Zn, Rb, Sr, and Ba originated from the rhyolite, rhyolitic tuff, and basalts. The rare earth element (REE) content of the geothermal waters is low, and according to the normalized REE diagrams, the light REE are getting depleted and heavy REE are getting enriched. The positive Eu and negative Ce anomalies of waters indicate oxygen-rich environments.     

Teleseismic finite-fault inversion of two <Emphasis Type="Italic">M</Emphasis><Subscript>w</Subscript> = 6.4 earthquakes along the East Anatolian Fault Zone in Turkey: the 1998 Adana and 2003 Bingöl earthquakes

The East Anatolian Fault Zone is a continental transform fault accommodating westward motion of the Anatolian fault. This study aims to investigate the source properties of two moderately large and damaging earthquakes which occurred along the transform fault in the last two decades using the teleseismic broadband P and SH body waveforms. The first earthquake, the 27 June 1998 Adana earthquake, occurred beneath the Adana basin, located close to the eastern extreme of Turkey’s Mediterranean coast. The faulting associated with the 1998 Adana earthquake is unilateral to the NE and confined to depths below 15 km with a length of 30 km along the strike (53°) and a dipping of 81° SE. The fixed-rake models fit the data less well than the variable-rake model. The main slip area centered at depth of about 27 km and to the NE of the hypocenter, covering a circular area of 10 km in diameter with a peak slip of about 60 cm. The slip model yields a seismic moment of 3.5?×?10¹⁸ N-m (M_w???6.4). The second earthquake, the 1 May 2003 Bingöl earthquake, occurred along a dextral conjugate fault of the East Anatolian Fault Zone. The preferred slip model with a seismic moment of 4.1?×?10¹⁸ N-m (M_w???6.4) suggests that the rupture was unilateral toward SE and was controlled by a failure of large asperity roughly circular in shape and centered at a depth of 5 km with peak displacement of about 55 cm. Our results suggest that the 1998 Adana earthquake did not occur on the mapped Göksun Yakap?nar Fault Zone but rather on a SE dipping unmapped fault that may be a split fault of it and buried under the thick (about 6 km) deposits of the Adana basin. For the 2003 Bingöl earthquake, the final slip model requires a rupture plane having 15° different strike than the most possible mapped fault.     

The measurement of soil gases and shallow temperature for determination of active faults in a geothermal area: a case study from Ömer–Gecek,Afyonkarahisar (West Anatolia)

Afyonkarahisar is a very important geothermal province of western Anatolia and has low and medium enthalpy geothermal areas. This study has been carried out for the preparation of distribution maps of soil gases (radon and carbon dioxide) and shallow soil temperature and the exploration of permeable tectonic regions associated with geothermal systems and reveal the origins of radon and carbon dioxide gases. The western district of the study area is characterized by the high radon concentration (168.30 kBq/m³), carbon dioxide ratio (0.30%), and soil temperature (21.0 °C) values. Fethibey and Demirçevre faults, which allow the circulation of geothermal fluids, have been detected in the distribution maps of radon, carbon dioxide, and shallow depth temperature and the directions of the curves in these maps correspond to the strikes of Demirçevre faults. The effect of the fault plays an important role in the change of carbon dioxide concentration along the W-E directional geological section prepared to determine the change of soil gas and shallow depth temperature values depending on lithological differences, fault existence, and geothermal reservoir depth. On the other hand, it was determined that Rn²²² concentration and soil temperature changed as a function of geothermal reservoir depth or lithological difference. Tuffs in Köprülü volcano-sedimentary units are the main source of radon due to their higher uranium contents. Besides, the carbon dioxide in Ömer–Gecek soils has geothermal origin because of the highest carbon dioxide content (99.3%) in non-condense gas. The similarities in patterns of soil temperature, radon, and carbon dioxide indicate that the variation in soil temperatures is related to radon and carbon dioxide emissions. It is concluded that soil gas and temperature measurements can be used to determine the active faults in the initial stage of geothermal exploration successfully.     

Effects of seismic force and pore water pressure on stability of 3D unsaturated hillslopes

Natural Hazards - Three-dimensional (3D) kinematic limit analysis of unsaturated hillslopes is presented in this paper. Different from the traditional two-dimensional (2D) mechanism based on the...     

Automatic detection of earthquake-induced ground failure effects through Faster R-CNN deep learning-based object detection using satellite images

Natural Hazards - The seismically induced ground failure is defined as any earthquake-generated process that leads to deformations within a soil medium, which in turn results in permanent...     

超临界态甲烷密度研究

超临界甲烷密度不仅是非常规天然气资源量计算与吸附能力测定的重要参数,同时也是衡量超临界甲烷扩散效率与溶解有机物能力的主要指标。通过对比分析各种气体状态方程的适用性,认为基于亥姆霍兹能量基本状态方程可以准确计算0~30 MPa、270~360 K条件下甲烷的密度。利用Microsoft Office Excel编写了甲烷密度的计算程序,与NIST （美国国家标准与技术研究院）商业软件计算结果相比,误差小于0.05%。分析了0~100 MPa、270~360 K范围内甲烷密度的变化规律。结果表明,甲烷密度随压力增大而增大,在低于30 MPa时增速较大且对温度的敏感性较强,高于30 MPa时增速逐渐变缓,且敏感性减弱。在煤层原位条件下随着埋深的增大,甲烷密度随温度升高而减小,随压力增大而增大;在温度与压力共同作用下,甲烷密度呈先增速不变、近似线性增加,后增速逐渐减小、凸曲线形增加的变化规律。游离态甲烷密度受温度的影响比吸附态甲烷小,是深部煤层气资源增量的主要贡献者。研究结果为深部煤层气赋存及其潜力预测提供了基础参数。      

High Resolution Optical Spectroscopy of a B-type Abundance Standard Candidate in Ori OB1—HD 35039

Astronomy Letters - We present LTE analysis of high resolution optical spectra for the B-type abundance standard candidate HD 35039 (HR 1765, 22 Ori) with an ambigous binary nature. The spectra...     

基于WoS和Citespace的应急避难场所知识图谱和进展分析

以近30 年Web of Science 核心数据库收录的2472 篇应急避难场所相关文献为基础,首先统计发文数量时间分布和期刊分布,然后利用Citespace可视化软件,从发文作者、机构、国家、关键词和学科方向5个方面分别进行知识图谱分析。结果表明：近30年来应急避难场所研究发文呈现由缓慢探索、稳步发展向高速发展的阶段;发文期刊主要为自然灾害类、紧急医学类、工程技术类;研究作者群较多,学术交流较为紧密;美国和中国为发文量最多的国家;路易斯安那州立大学和中国科学技术大学是主要的发文机构;从关键词发现应急避难场所目标人群主要围绕灾害救援和社会弱势群体,研究视角从单一问题和事件开始向综合系统演变,研究方法从定性的方法模型转向动力机制和信息系统开发,研究内容则注重多学科交叉和微观尺度、重视案例实证和信息共享和强调应急避难场所管理;学科方向主要为工程学和公共环境与健康两个学科。在建设韧性城市的背景下,可借鉴国际经验来构建中国应急避难场所研究体系和管理。     

Dynamical system analysis of a five-dimensional cosmological model

A five-dimensional cosmological model including a single perfect fluid is studied in the framework of dynamical system analysis. All the critical points of the system are listed with their stability properties and some representative phase diagrams are explicitly shown. It is found that the stabilization of extra dimension is possible and the observed flatness of the three-dimensional space is provided for certain ranges of the equation of state parameter of the fluid. The model suggested here can be considered as a simplified model for examining the possible effects of the extra dimensions in the early universe.