Crustal structure and local seismicity in western Anatolia

Western Anatolia is one of the most seismically active continental regions in the world and much of it has been undergoing NS-directed extensional deformation since Early Miocene time. In a cooperative study, seismologists from Saint Louis University, USA and Dokuz Eylül University, Turkey, deployed five broad-band and 45 short-period seismic stations in western Anatolia between 2002 November and 2003 October. The present paper uses data collected by this network and the data from five permanent stations operated by the Kandilli Observatory and Earthquake Research Institute to map the hypocentral distribution of local earthquakes and to determine crustal structure of western Anatolia. We obtained a 1-D P -wave crustal velocity model using a generalized scheme for simultaneously obtaining earthquake locations and a crustal velocity model. Our velocity model is characterized by crustal velocities that are significantly lower than average continental values. The low velocities may be associated with high crustal temperatures, a high degree of fracture, or the presence of fluids at high pore pressure in the crust. We located 725 local earthquakes and classified them in three categories. We found that the level of seismic activity in western Anatolia is higher than previously reported. Station delays resulting from the inversion process correlate with near-surface geology and the thickness of sediments throughout the region. The hypocentral distribution of the events indicates that peak seismicity for the region occurs at depths of about 10 km.     

关于亚洲与非洲分界线的讨论

本文从阿拉伯半岛的地壳运动，板块构造，地貌，气候、植被方面探讨其与北非的类同性和与西亚安纳托利亚高原，伊朗高原的差异性，得出阿拉伯半岛应属非洲的结论，并划出一条新的亚、非两洲的分界线。     

Tectonic implications of transtensional supradetachment basin development in an extension‐parallel transfer zone: the Kocaçay Basin,western Anatolia,Turkey

The Kocaçay Basin (KÇB) is a key area in western Anatolia – a well‐known extended terrane where regional segmentation has received limited attention – for investigating strike‐slip faults kinematically linked to detachment faults. In this paper, we present results of an integrated sedimentologic, stratigraphic, and structural study of Miocene alluvial fan/fan‐delta/lacustrine deposits that accumulated in the KÇB, a NE‐trending basin with connections to the Menderes Metamorphic Core Complex (MCC). We mapped and evaluated most of the key faults in the KÇB, many for the first time, and recognised different deformation events in the study area near the E margin of the MCC. We also present field evidence for kinematic connections between low‐angle normal and strike‐slip faults which were developed in an intermittently active basement‐involved transfer zone in western Anatolia. We find that the KÇB contains a detailed record of Miocene transtensional sedimentation and volcanism that accompanied exhumation of the MCC. Structural data reveal that the basin was initially formed by transtension (D1 phase) and subsequently uplifted and deformed, probably as a result of early Pliocene wrench‐ to extension‐dominated deformation (D2 phase) overprinted by Plio‐Quaternary extensional tectonics (D3 phase). These results are consistent with progressive deformation wherein the axis of maximum extension remained in the horizontal plane but the intermediate and maximum shortening axes switched position in the vertical plane. Combining our results with published studies, we propose a new working hypothesis that the KÇB was a transtensional supradetachment basin during the Miocene. The hypothesis could provide new insights into intermittently active extension‐parallel zone of weakness in western Anatolia.These results also suggest that the termination of low‐angle normal fault systems within an extension parallel transfer zone may have resulted in a transtensional depressions which are different from classical supradetachment basins with respect to the sedimentation and deformational pattern of the basin infills.     

A 2300-year record of environmental change from SW Anatolia, Lake Burdur, Turkey

This work deals with changes recorded by lacustrine sediments from SW Anatolia in Turkey in the context of increasing stress on the Mediterranean environment in relation to human-climate-environmental interactions. Paleolimnological investigations were carried out on Lake Burdur (Lake District geographical subregion of Turkey), which has been subject to rapid changes in its hydrological system that caused a ~10-m water-level drop in the last 30 years. Study of a 5-m-long sediment core, taken from the recently dried out part of the lake, shows significant variation in granulometry, clay mineralogy, nitrogen and organic carbon content and its isotopic composition (?¹³C_org) throughout the sedimentary sequence, which represents the last 2,300 years. Chronology is based on radiocarbon dates obtained from plant fragments. The results provide a record of environmental changes, including biological productivity and erosion intensity, in relation to changes in water level and humidity of the area. The lowest previous water level, which is the same as observed today, occurred at approximately 300 BC, after which time a water-level increase led to a maximum stage between AD 200 and 1200. From AD 1200 to the present, the climate became drier accompanied by an overall lowering of water level, with periods of water-level fluctuations superimposed. The lake never dried out as is observed today at the coring site. The present drop in the lake water level is attributed to human activity rather than to climate change. This record of climate and environmental change in the Lake Burdur area appears to be stratigraphically complete. This study provides rare data for the late Holocene in Anatolia as well as information about rapid climate changes during specific periods. The influence of both the Northern hemisphere atmospheric circulation and Indian monsoon on the east Mediterranean remains unclear. Nevertheless, the North Sea—Caspian atmospheric teleconnection could be an important factor that explains local differences in climatic evolution of Anatolia during the period considered.     

Drainage response to Arabia–Eurasia collision: Insights from provenance examination of the Cyprian Kythrea flysch (Eastern Mediterranean Basin)

The Cenozoic geodynamics of the north‐eastern Mediterranean Basin have been dominated by the subduction of the African Plate under Eurasia. A trench‐parallel crustal‐scale thrust system (Misis–Kyrenia Thrust System) dissects the southern margin of the overriding plate and forms the structural grain and surface expression of northern Cyprus. Late Eocene to Miocene flysch of the Kythrea (De?irmenlik) Group is exposed throughout northern Cyprus, both at the hanging‐wall and foot‐wall of the thrust system, permitting access to an extensive Cenozoic sedimentary record of the basin. We report the results of a combined examination of detrital zircon and rutile U–Pb geochronology (572 concordant ages), coupled with Th/U ratios, Hf isotopic data and quantitative assessment of grain morphology of detrital zircon from four formations (5 samples) from the Kythrea flysch. These data provide a line of independent evidence for the existence of two different sediment transportation systems that discharged detritus into the basin between the late Eocene and late Miocene. Unique characteristics of each transport system are defined and a sediment unmixing calculation is demonstrated and explained. The first system transported almost exclusively North Gondwana‐type, Precambrian‐aged detrital zircon sourced from siliciclastic rock units in southern Anatolia. A different drainage system is revealed by the middle to late Miocene flysch sequence that is dominated by Late Cretaceous–Cenozoic‐aged detrital zircon, whose age range is consistent with the magmatic episodicity of southeast Anatolia, along the Arabia–Eurasia suture zone. Deposition of these late Miocene strata took place thereupon closure of the Tethyan Seaway and African–Eurasian faunal exchange, and overlap in time with a pronounced uplift of eastern Anatolia. Our analytical data indicate the onset of prominent suture‐parallel sediment transport from the collision zone of south‐eastern Anatolia into the Kyrenia Range of northern Cyprus, marking the drainage response to the continental collision between Arabia and Eurasia.     

中国人口家庭式迁移研究的知识图谱分析

随着“十四五”时期以人为核心的新型城镇化战略的深入推进,家庭式迁移作为现阶段中国人口迁移的主要模式,对加快实现流动人口市民化有着重要意义。文章采用文献计量方法和CiteSpace可视化技术对1996—2018年的452篇相关文献进行定量分析,绘制出研究的关键词、发文作者、发文机构的知识图谱,对国内家庭式迁移研究现状进行分析与总结。结果表明：①国内家庭式迁移研究总体呈现良好态势。研究热点持续升温,研究主题趋向多元化,并呈现多学科交叉的趋势。②研究作者群体呈现出总体分散、局部集中的特征,已形成一批学术代表,研究团队之间的合作度不高,学术交流有待加强。③研究机构主要是全国各地的高校和科研院所,机构之间的学术合作不够。④研究热点主要围绕家庭式迁移的过程、特征和影响因素,家庭式迁移与新型城镇化发展以及家庭式迁移带来的子女教育和就业问题等方面展开。未来相关研究应以流动家庭为核心,融入空间与地方、身体、日常生活实践和流动性等多理论视角,进一步加强人口家庭式迁移的社会文化维度的探讨与本土化理论的创新。     

THE PERSISTENCE OF CANADIAN TOWNS AND VILLAGES: SMALL IS VIABLE

Intraurban migration theory suggests that locational decisions are a function of housing subsectors, defined by quality, price, location, and tenure. The development of foreign ghettos in German cities is expected to increase if the intraurban migration and emigration-immigration behavior of Germans and foreigners is different among housing subsectors. In D'bsseldorf, five housing subsectors are present. Only the German population indicates differentiation between sectors. Differences in the individual foreigner nationalities are small, and the number of each group resident in a sector is the best indicator of future migration. On the basis of four years of migration data for a typical German city, it is projected that future ghetto formation in West Germany will be slow and hindered by the tight German housing market.     

Spain. Regional differences in population density in 1986: the end of a process of increasing internal disequilibrium?

This is an analysis of regional differences in population trends in Spain during the twentieth century. Data are from a variety of official sources, including the censuses of 1900, 1960, 1970, and 1981. The author notes that up until 1975, interregional migration flows had acccentuated regional economic differences. However, the economic problems that have occurred since 1975, coupled with the political changes associated with greater regional autonomy, have resulted in new trends in internal migration that could have significant effects on the future distribution of the country's population.     

ETHNIC DIFFERENCES IN MIGRATION PATTERNS—DISPARITIES AMONG ARABS AND JEWS IN THE PERIPHERAL REGIONS OF ISRAEL*

Studies of migration patterns in national peripheries of countries do not distinguish between different population groups in these regions. The present study examines spatial patterns of Arab and Jewish populations in Israel's national periphery. The migration trends of Arabs and Jews in the northern national periphery (the Galilee) are compared with those of the southern national periphery (the Negev). The Arab and Jewish populations within these areas show different spatial patterns of migration: in both the northern and the southern peripheries, Jews tend to migrate from the periphery to the core, while Arabs tend to migrate within the periphery. These differences increase the ratio of Arabs to Jews in both regions. The findings suggest that researchers should examine subregions and subgroups when studying migration patterns.     

WHEN A RESIDENCE IS NOT A HOUSE: EXAMINING RESIDENCE-BASED MIGRATION DEFINITIONS

Traditional definitions of migration contain implicit assumptions: origin and destination places are fixed residences, households inhabit one residence at any given time, and dwelling units form the center of individual activity spaces. Though these assumptions hold for certain movers, they restrict migration studies to a narrow range of movement. It is argued here that such assumptions bias present notions of migrant behavior and selectivity. A more realistic appraisal might consider integration in sets of spatial networks rather than movement between two discrete points in space.     

1995—2015年中国省际人口迁移网络的演化特征——基于异质性劳动力视角

自户籍制度放宽以来,中国经历了大规模的人口迁移。其中,异质性劳动力（高技能劳动力、普通劳动力）在迁移过程中表征出不同的空间格局和网络组织特征,对地区经济发展产生各异的影响。本研究基于人口普查和抽样调查微观抽样数据,使用复杂网络理论对1995—2015年中国异质性劳动力迁移的时空格局和网络演化展开分析,并分析了格局背后的可能成因。研究发现：① 省际高技能和普通劳动力迁移均呈现出持续高度不平衡的空间集聚特征,承载大量人口的迁移流主要由中国中西部地区指向东部沿海地区,但这种空间不平衡特征呈现出一定的减弱趋势。高技能劳动力的平均迁移距离比普通劳动力更长;② 两类劳动力迁移网络中均呈现明显的“小世界”特性,但普通劳动力迁移网络的迁移强度和关联程度均高于高技能劳动力迁移网络;③ 两类劳动力迁移网络均呈现出以北京、上海、广东为主要核心节点的网络结构。高技能劳动力网络结构呈现相对稳定的特征,而普通劳动力网络结构则呈现出变化的趋势;④ 地区经济差异、路径依赖效应、异质性劳动力在就业市场上的差异性以及劳动力市场对异质性劳动力需求的差异是导致两类劳动力迁移格局差异性的重要成因。     

省际人口迁移与制造业转移空间交互响应研究

基于2000年、2005年、2010年和2015年人口普查与1%人口抽样调查数据以及相关年度制造业统计数据,利用重心模型和地理探测器对2000年以来的不同类型制造业转移空间格局、人口流动空间格局及其二者相互作用关系进行分析。研究发现： 2000年以来特别是2005年之后中国制造业呈现出明显转移态势,但不同类型制造业转移幅度和空间区域具有明显差异,能源密集型、技术密集型、资本密集型制造业由东部向中西部转移的空间区域大,劳动密集型产业转移空间还十分有限,仍集中于东部地区。 虽然人口迁移的整体格局变化不大,仍是“中间低、周边高”的格局,但是人口迁移的空间特征正在趋于弱化,中西部地区分享的迁入人口份额在不断提高。 制造业重心与人口迁移重心变动轨迹呈现出“偏离-趋同”关系,人口迁移滞后于产业转移的效应已逐渐消失,人口与产业的空间匹配程度趋于提高。 地理探测器定量识别人口迁移与制造业转移之间的空间关系发现,人口迁移格局变化对制造业空间转移的响应程度较制造业转移对人口迁移格局变化的响应程度高。     

生态系统退化的人类响应（英文）

生态系统为人类提供了必要的服务,其中大部分是没有市场价格的,因此被认为是"自然的免费赠品"而被大量使用。近年来由于快速的工业化和城市化,不断增长的人口已经使人们认识到生态系统服务也是有限的。环境退化是用来描述生态系统服务的损失或损害的常用指标,而移民往往是环境恶化的后果。那么,生态系统服务退化到什么程度才足以导致人们搬迁?本文通过对移民和环境退化相关文献的综述,力求寻求及时监测生态系统退化状况、避免人类承受生态移民痛苦、探求不同环境下人类更好地生存与发展的途径。     

互联网时代中澳间相互作用类型、演变与形成机理

互联网对空间相互作用的影响研究是地理学的重要命题。该文以互联网时代中澳间在总体及物流、资金流和人流3个具体方面作用现状为分析基础,确定出当前中澳相互作用的类型,进而划分了演变所经历的4个阶段。其后揭示了中澳相互作用流的形成机理,指出高层互访和一系列重要协议的签署是两国间相互作用的催化剂。最后总结出互联网时代中澳相互作用的3点特征,即信息流、人流和物流流动的异路性;资金流、留学流和移民流流动的显著单向性;以及距离因素作用的相对弱化。     

Questions of emigration,circulation and return: mobility between the French Caribbean and France

"The last four decades have seen the establishment of close migratory links between the French Caribbean islands of Martinique and Guadeloupe and the metropole.... The present paper focuses on the...complex migratory links--including continuing emigration from the islands for work and education, return migration and circulation--which have come to characterise the 1980s.... The paper aims also to contribute to the broader conceptualisation of migration and mobility. The principal conclusions reveal that the more straightforward labour migration of the years from 1963 to 1981 has been replaced by some considerable return migration (amongst young adults particularly) and circulation.... The paper also demonstrates that the role of migration in reducing population growth and fertility in the islands has been much altered during the course of the 1980s."     

企业迁移研究进展

企业迁移研究对区域经济统筹发展、区域政策的制定具有重要的指导意义．本研究通过梳理国内外相关文献,从企业迁移的类型、三大基础理论学派的对比和国内外在实证研究的研究内容和方法上的差异等3个方面对企业迁移研究进行了较为系统的回顾与总结,并提出未来研究的展望,指出企业迁移的内部因素、企业迁移与区域经济发展的关系、企业迁移的绩效研究等应成为未来研究的重点领域．     

Economic Opportunities and Internal Migration: A Case Study of Guangdong Province,China*

Economic opportunities are considered a primary determinant of human migration, but their explanatory power in Communist China has been limited because of strong government intervention in controlling migration and in planned population transfers. Since the late 1970s, however, economic reform has brought about changes in China's regional economies and generated new push and pull forces for migration, and the relaxation of migration restrictions has created greater opportunities for nongovernment-induced migration. Using data primarily from the 1990 census, I review the spatial patterns of migration and the characteristics of the new migrants. A case study of Guangdong Province reveals that its attractiveness to migrants from other provinces and its intra-provincial migration patterns are attributable to differentials in per capita output and foreign investment. The findings support the argument that China has entered a new era of migration in which present and expected economic opportunities are important explanations for the volume and directions of population movement.     

20世纪末中国迁移人口空间分布格局——基于城市的视角

基于人口普查资料,对20世纪末中国迁移人口在不同行政级别、不同规模城市的分布格局进行分析,并运用探索性空间数据分析技术进一步对地级及以上城市迁移人口的空间分布特征进行研究。结果表明:地级及以上城市在迁移人口流动中占主要地位,其中百万规模级别以上城市在人口迁移中地位尤为显著;县级市间迁移人口规模差异显著,东部地区县级市平均迁移规模要大于西部和中部;省际迁移中城市空间分布大体呈现3个梯状层次;省内迁移中城市空间分布总体表现出极大的相似性,均以各省会城市作为省内迁移人口的第一流入地;不论是省内迁移还是省际迁移,东部沿海地区的珠三角和长三角地区城市群都是迁移人口的高度集聚地。     

农村劳动力回流的影响因素分析——以广东省云浮市为例

改革开放以来,中国大规模的人口流动对资源的优化配置和经济快速发展产生了深远的影响.然而,中国的农村劳动力流动正逐渐从单向转变为城乡双向流动的格局,这一变化无疑将深刻影响我国农村地区的发展前景.文中采用对广东省云浮市农户的调查数据,通过构建Logistic模型,从农村外出劳动力个体行为决策的视角探讨农村劳动力回流的影响因素.实证研究表明:人力资本较低,年龄偏大,家庭儿童数量较多、老人数量较少和已婚的外出劳动力回流的可能性较大;而外出务工时间对回流概率的影响呈倒U型分布;家乡的非农就业机会与村庄的区位因素也显     

中国电力强度重心迁移及差异研究

电力资源在中国能源建设以及能源发展方式转变中处于中心地位,全面降低电力强度是实现资源、经济、环境可持续发展的关键所在。研究中国电力强度重心迁移路径以及区域差异可以厘清电力强度分布状况,对实现上述目标具有现实意义。本文运用重心理论研究了中国1985-2014年电力强度重心迁移路径,进而采用泰尔指数计算并分解了电力强度非均衡程度。研究结果表明：1985-2014年,电力强度总体上呈现出持续向西迁移的态势。期间,1985-1993、2003-2014年主要体现为向西北方向移动,1993-2003年则表现为向西南方向移动的特征。1985-2000年,区域间及区域内部差异对于重心迁移的贡献率各占50%;2000-2014年,演变推力主要来源于区域内部差异,贡献率均值为54.49%,内部差异则受西北、西南、华北地区影响最大。