山西历史强震震中和沉降中心的关系

根据对历史地震震中和山西断陷带内沉降中心的研究,发现该带内的强震震中与沉降中心有很好的对应关系。以现有的资料为基础,统计了各沉降中心内第四系与新生界的比值(Q/Kz)。结果表明,强震的发生与沉降中心的 Q/Kz值有一定的对应规律。根据这一结果,近一步讨论了512年7 1/2级地震的震中位置。     

龙门山中段推覆构造带及相关构造的演化历史和变形机制（二）

川西前陆盆地是从晚三叠世晚期（须家河期）以来开始发育的，其形成是龙门山推覆构造带自北西往南东持续推覆的结果。本区的构造发展经历了伸展裂陷、构造反转和持续推覆３个主要阶段。构造变形的力源主要来自松潘－甘孜褶皱带的北东～南西向收缩派生的南东向挤压     

Decentralization of Retailing in Britain: The Breaking of the Third Wave

A much anticipated explosion in regional shopping center retailing in Britain has failed to emerge. This paper suggests that the threat to existing property investments was a key reason why funds for development were slow to materialize. By the time the movement gathered pace, the British government became worried by the scale of proposals. Since the consumer boom that followed the expansionary budget of 1988 was short lived, it follows that many potential investors were relieved that they did not become involved with schemes that might have had little economic viability. Therefore, the rather restricted geography of retailing in Britain has been left largely unchanged.     

The Reykjanes Ridge: structure and tectonics of a hot-spot-influenced, slow-spreading ridge, from multibeam bathymetry, gravity and magnetic investigations

We report a comprehensive morphological, gravity and magnetic survey of the oblique- and slow-spreading Reykjanes Ridge near the Iceland mantle plume. The survey extends from 57.9°N to 62.1°N and from the spreading axis to between 30 km (3 Ma) and 100 km (10 Ma) off-axis; it includes 100 km of one arm of a diachronous ‘V-shaped' or ‘chevron' ridge. Observed isochrons are extremely linear and 28° oblique to the spreading normal with no significant offsets. Along-axis there are ubiquitous, en-echelon axial volcanic ridges (AVRs), sub-normal to the spreading direction, with average spacing of 14 km and overlap of about one third of their lengths. Relict AVRs occur off-axis, but are most obvious where there has been least axial faulting, suggesting that elsewhere they are rapidly eroded tectonically. AVRs maintain similar plan views but have reduced heights nearer Iceland. They are flanked by normal faults sub-parallel to the ridge axis, the innermost of which occur slightly closer to the axis towards Iceland, suggesting a gradual reduction of the effective lithospheric thickness there. Generally, the amplitude of faulting decreases towards Iceland. We interpret this pattern of AVRs and faults as the response of the lithosphere to oblique spreading, as suggested by theory and physical modelling. An axial, 10–15 km wide zone of high acoustic backscatter marks the most recent volcanic activity. The zone's width is independent of the presence of a median valley, so axial volcanism is not primarily delimited by median valley walls, but is probably controlled by the lateral distance that the oblique AVRs can propagate into off-axis lithosphere. The mantle Bouguer anomaly (MBA) exhibits little mid- to short-wavelength variation above a few milliGals, and along-axis variations are small compared with other parts of the Mid-Atlantic Ridge. Nevertheless, there are small axial deeps and MBA highs spaced some 130 km along-axis that may represent subdued third-order segment boundaries. They lack coherent off-axis traces and cannot be linked to Oligocene fracture zones on the ridge flanks. The surveyed chevron ridge is morphologically discontinuous, comprising several parallel bands of closely spaced, elevated blocks. These reflect the surrounding tectonic fabric but have higher fault scarps. There is no evidence for off-axis volcanism or greater abundance of seamounts on the chevron. Free-air gravity over it is greater than expected from the observed bathymetry, suggesting compensation via regional rather than pointwise isostasy. Most of the observed variation along the ridge can be ascribed to varying distance from the mantle plume, reflecting changes in mantle temperature and consequently in crustal thickness and lithospheric strength. However, a second-order variation is superimposed. In particular, between 59°30′N and 61°30′N there is a minimum of large-scale faulting and crustal magnetisation, maximum density of seamounts, and maximum axial free-air gravity high. To the north the scale of faulting increases slightly, seamounts are less common, and there is a relative axial free-air low. We interpret the 59°30′N to 61°30′N region as where the latest chevron ridge intersects the Reykjanes Ridge axis, and suggest that the morphological changes that culminate there reflect a local temperature high associated with a transient pulse of high plume output at its apex.     

Late amagmatic extension along the central and eastern segments of the West Philippine Basin fossil spreading axis

The spreading processes within the West Philippine Basin (WPB) remain partly unknown. This study presents an analysis of the tectono-magmatic processes that happened along its spreading axis during the conclusion of the last spreading phase at 33/30 Ma. We demonstrate that the late episode of N-S opening from an E-W-trending spreading system has been followed by a late tectonic event occurring in the central and eastern parts of the basin. This event was responsible for transtensional strain accommodated along the NW-SE faults cutting through the former E-W rift valley in the central part of the basin. In its eastern part, the same event occurred at a larger extent and led to the creation of a new NW-SE axis, obliquely cutting the older E-W spreading segments and their associated spreading fabrics. At this location, several tens of kilometers of slightly oblique amagmatic extension occurred following a ∼60° direction. We propose that this late event is associated with the onset of E-W opening of the Parece-Vela Basin located along the eastern border of the WPB at 30 Ma. Extensive stresses within this basin were probably transmitted to the hot and easily deformable rift zone of the WPB. The newly-created NW-SE axis most likely propagated from east to west, being responsible for scissors opening within the WPB. NE-SW extension ceased when well-organized spreading started at 26 Ma in Parece-Vela Basin, accommodating entirely the global extensive stress pattern.     

南京都市区就业空间结构与区位模式演变研究

就业空间是城市空间的重要组成部分,映射出城市经济与社会现象的多样性。论文采用经验贝叶斯克里金、非参数局部加权回归、多中心密度函数等方法综合刻画南京都市区就业空间结构特征,并从就业结构化分散、就业中心增长转型、就业异质性集聚与土地混合利用3个方面剖析其就业区位模式特征。研究发现：① 南京都市区就业郊区化与多中心化并存,“分散化集聚”的结构性特征显著;② 就业中心决定着就业空间的整体结构与密度分布,然而城市中心影响力开始减弱而次中心则逐渐增强;③ 就业中心出现增长转型,服务化转向与高技能化趋势明显;④ 就业分布呈现异质性集聚模式且与混合土地利用存在正向关联;⑤ 城市就业空间格局演变是自组织与他组织2种力量、市场行为与政府行为2种机制相互作用的结果,集聚经济、城市规划、土地市场开发等均是重要的影响因子。     

Creating and sustaining Islamic financial centers: Bahrain in the wake of financial and political crises

Although primarily concentrated in countries with Muslim majorities, Islamic finance has become a global industry representing both a decentering of the global financial architecture and the emergence of an urban network that resides beyond the confines of traditional world city literature. While geographers have identified the “Mecca’s” of the Islamic finance industry – one of which is Bahrain – there remains a need to identify the factors necessary to create and sustain centers of Islamic finance. This paper examines these factors through a firm-level survey of foreign and local Islamic financial institutions in Bahrain, in conjunction with key informant interviews with representatives of these firms. We find that while Bahrain’s entrenched institutional advantages have preserved its role as a center in the Islamic financial landscape, ongoing political instability and the increasing attractiveness of new and emerging centers are threatening this role. As the country navigates the current social and political unrest, questions are raised as to what it takes to be an Islamic financial center.     

三门峡水库冲淤重心变化及其对潼关高程的影响

以往关于三门峡水库的研究多关注库区年际间的冲淤变化,而对汛期和非汛期库区冲淤分布研究较少。本文基于三门峡水库蓄清排浑运用以来1974 2018年实测水沙、断面及冲淤数据,研究汛期和非汛期库区冲淤重心的迁移、冲淤速率及其对潼关高程的影响。结果表明,蓄清排浑运用以来库区河道基本遵循汛期冲刷、非汛期淤积的演变规律。分别定义汛期最大冲刷速率和非汛期最大淤积速率发生的相邻两断面间的子河段为冲刷重心和淤积重心,汛期冲刷重心与非汛期淤积重心出现的位置基本对应,1974 2010年冲淤重心由距坝约90 km逐渐向坝前移动,平均下移速率约1～2km/a;2010年后冲淤重心逐渐上移,2017年位于坝上游约60～70 km,但冲淤强度明显减弱。淤积重心的位置主要受水库回水长度影响,冲刷重心主要与汛期水流能量相关,淤积重心位置迁移滞后于影响因子的变化约5年,而冲刷重心滞后时间约2年。潼关高程与潼关至太安段（潼太段）比降呈反比关系,比降越大,潼关高程越低,而当冲刷重心迁移至潼太段并影响其下段时,潼太段比降增大,利于潼关高程降低。1985年后回水范围和冲淤重心均位于潼关以下,潼关高程受冲淤重心影响较小。     

基于不同尺度的中国运动健身场所空间差异及影响因素研究

运动健身场所是开展全民健身运动的重要推手,探明运动健身场所的区域差异及影响因素对推动运动健身场所的建设、推进“健康中国”战略有重要作用。从省级、城市群以及地级市3个尺度出发,运用总体分异测度指数(Global differentiation index,GDI)、Moran’s I指数、热点分析探讨运动健身场所的空间差异,采用Pearson相关系数、灰色关联度以及地理探测器等方法分析运动健身场所分布的影响因素。结果表明:(1)运动健身场所数量与每万人拥有运动健身场所数量主要集中分布于东部地区,而西部地区除成都、重庆外,其余省区均分布较少。(2)运动健身场所数量与每万人拥有运动健身场所数量的GDI随着尺度的缩小而扩大,城市群尺度中,优化提升类差异最大,而发展壮大类差异最小。(3)经济总量和人口数量是运动健身场所集中的重要驱动因素,人口数量与城镇人口占比的交互作用最强。在城市群尺度上,受教育程度和城市规模大小是运动场所的重要影响因素。而在地级市尺度上,建成区面积占辖区面积比重对运动健身场所的影响更为显著。