全球大陆7级浅源大地震强余震震级和空间分布特征

本文收集了1967—2007年全球大陆(不包括中国大陆)29次7.0～7.9级浅源大地震的余震资料。根据震源机制解结果把这29次地震序列分为走滑型和非走滑型,其中17次是走滑型,12次是非走滑型,并分别研究了走滑型和非走滑型地震序列强余震震级分布特征和空间分布特征。研究结果表明,强余震与主震震级差服从指数分布,统计得到了走滑型地震序列B值为0.58,非走滑型地震序列B值为1.07。走滑型地震序列强余震与主震距离的优势分布范围是10～45km,而非走滑型地震序列强余震与主震的距离优势分布为20～59km,并且强余震与主震震中距服从正态分布。

全球大陆末次盛冰期气候和植被研究进展

未次盛冰期（ＬＧＭ）是太阳辐射异常处于极低值、北半球第四纪冰流规模处于峰值、两万年来距人类环境最近但与现代气候有着巨大反差的特殊时期．７０年代以来由于新资料不断积累、气候模拟技术发展、海洋大陆冰流各圈层的相关和偶合、传统的气候指标和新的气候指标的认识和应用、以及区域性和全球性的国际合作，在ＬＧＭ古气候环境领域已经取得了巨大进展本文根据数个国际ＬＧＭ合作计划研究成果，综述９０年代以来全球对ＬＧＭ研究方法途径和大陆古气候植被研究成果，并对其前景提出雏议。

全球大陆中深源地震机理科学问题——兼论人体科学与地震预测国际研究动态

本文系统阐述全球大陆中深源地震分布、大陆中深源地震机理、大陆动力学与中深源地震,我们研究中国大陆地震活动与地球动力学的关系,是一个非常重要的科学课题。人体科学与地震预测国际研究动态,人体感应将成为一种新的预测灾难的手段,人体感应将为国家的防灾减灾事业增添新理论、新方法、新思路。

全球火山活动时空分布特征及其对强震活动趋势的指示

基于史密森学会火山目录分析了全球火山活动的时空特征,并结合中国地震台网目录讨论了火山活动对全球和中国大陆强震活动趋势的指示意义。结果显示:①全球火山活动表现出较为显著的百年周期特征,且百年周期内火山活动和M≥8.0大震之间存在着频次准同步和能量互补现象;②中国大陆1955年前后强震活动状态的变化可能与同期全球火山活动状态变化密切相关,且二者可能受控于百年周期内地球内部能量积累与释放的状态变化;③2022年汤加火山的剧烈喷发意味着地球内部能量仍在持续释放。结合全球M8地震和中国大陆M7浅源地震的活动特征,认为当前及未来一段时间全球及中国大陆的大震活动状态可能与二十世纪上半叶相似。

中新生代大陆运动学模式与大陆动力学机制的新认识

本文首次提出中新生代大陆聚散与洋壳更新过程，在运动学上属于球面二维螺旋运动；它是地幔环流三维螺旋运动的球面反映。地幔三维螺旋运动的成因机制是地幔径向环流与其绕地轴的旋转运动相耦合的结果；在运动学上，它与地球大气及海洋环流的三维螺旋运动性质相同，都与地球旋转运动有成因联系；它们的差别在于大气及海洋热对流源于太阳热辐射与地球重力作用，而地幔热对流之热能则源于地球内部。本文提出了地球各层圈物质运动的热力学过程与地球天体运动存在有机联系的证据，阐明了建立地球系统科学的方向。

ASTER项目简介

ＡＳＴＥＲ项目简介分类号ＴＰ７３２．２由日本通产省（ＭＩＴＩ）开发的高级星载热发射和反射辐射仪（ＡＳＴＥＲ），将于１９９８年搭载在ＮＡＳＡ的ＥＯＳ－ＡＭ－１平台上。发射ＡＳＴＥＲ的主要目的是深入了解地球表面或近地表以及较低大气层发生的各种局部和区域尺...

Eurasian Winter Cooling: Intercomparison of Reanalyses and CMIP5 Data Sets

A cooling trend in wintertime surface air temperature over continental Eurasia has been identified in reanalysis and the Coupled Model Inter-comparison Project phase 5(CMIP5)‘historical’simulations over the period 1989–2009.Here the authors have shown that this cooling trend is related to changes in Arctic sea-ice around the Barents-Kara seas.This study illustrates a consistent spatial and temporal structure of the wintertime temperature variability centered over Asia using state-of-the-art reanalyses and global climate model datasets.Our findings indicate that there is a physical basis for seasonal predictions of near-surface temperatures over continental Asia based on changes to the ice-cover in the Barents-Kara seas.

The New Challenges on the Silk Road

In his book Out of Control, Brzezinski speaks about a vacuum in Eurasia, with important geopolitical consequences. Which are the new challenges and risks on the Silk Road in the time of globalization, radicalization, and freedom of movement？ The paper will stress three challenges： the project ＂Economic zone on the Silk Road＂ （the leadership in economic performance is held by China and therefore the eastern political cultures have the necessary economic basis for asserting their independence）, the influence of ETIM and IMU on the region and the role and place of Xinjiang, as a bridge between Central and South Asia; how they reflected on this way of old traditions and cultures and whether there is a ＂clash＂ between the Eastern religions on the ＂Silk Road＂ and Islam with its multi dimensions, between the thick black chador and the silk veil, called ＂tissue of wind＂, between spiritual, transcendental cognition （Daoism） and pragmatic mundane faith of Islam. I will conclude that the new challenges on the Silk Road create new borders between people--religious, linguistic, ethnical, and new identities. The main question is as follows： Shall we keep the cultural plurality and authenticity of the region？

Contrast patterns and trends of lapse rates calculated from near-surface air and land surface temperatures in China from 1961 to 2014

The near-surface lapse rate reflects the atmospheric stability above the surface.Lapse rates calculated from land surface temperature(γTs)and near-surface air temperature( γTa )have been widely used.However,γTs and γTa have different sensitivity to local surface energy balance and large-scale energy transport and therefore they may have diverse spatial and temporal variability,which has not been clearly illustrated in existing studies.In this study,we calculated and compared γTa and γTs at^2200 stations over China from 1961 to 2014.This study finds that γTa and γTs have a similar multiyear national average(0.53°C/100 m)and seasonal cycle.Nevertheless,γTs shows steeper multiyear average than γTa at high latitudes,and γTs in summer is steeper than γTa ,especially in Northwest China.The North China shows the shallowest γTa and γTs,then inhibiting the vertical diffusion of air pollutants and further reducing the lapse rates due to accumulation of pollutants.Moreover,the long-term trend signs for γTa and γTs are opposite in northern China.However,the trends in γTa and γTs are both negative in Southwest China and positive in Southeast China.Surface incident solar radiation,surface downward longwave radiation and precipitant frequency jointly can account for 80%and 75%of the long-term trends in γTa and γTs in China,respectively,which provides an explanation of trends of γTa and γTs from perspective of surface energy balance.

Global wood anatomical perspective on the onset of the Late Antique Little Ice Age (LALIA) in the mid-6th century CE

Linked to major volcanic eruptions around 536 and 540 CE, the onset of the Late Antique Little Ice Age has been described as the coldest period of the past two millennia. The exact timing and spatial extent of this exceptional cold phase are, however, still under debate because of the limited resolution and geographical distribution of the available proxy archives. Here, we use 106 wood anatomical thin sections from 23forest sites and 20 tree species in both hemispheres to search for cell-level fingerprints of ephemeral summer cooling between 530 and 550 CE. After cross-dating and double-staining, we identified 89Blue Rings(lack of cell wall lignification), nine Frost Rings(cell deformation and collapse), and 93Light Rings(reduced cell wall thickening) in the Northern Hemisphere. Our network reveals evidence for the strongest temperature depression between mid-July and early-August 536 CE across North America and Eurasia, whereas more localised cold spells occurred in the summers of 532, 540–43, and548 CE. The lack of anatomical signatures in the austral trees suggests limited incursion of stratospheric volcanic aerosol into the Southern Hemisphere extra-tropics, that any forcing was mitigated by atmosphere-ocean dynamical responses and/or concentrated outside the growing season, or a combination of factors. Our findings demonstrate the advantage of wood anatomical investigations over traditional dendrochronological measurements, provide a benchmark for Earth system models, support cross-disciplinary studies into the entanglements of climate and history, and question the relevance of global climate averages.

Prevalent thickening and local thinning of the mantle transition zone beneath the Baikal rift zone and its dynamic implications

The Baikal rift is the most seismically active continental rift in the world and is significant for studying the dynamics of continental rifts, although its precise dynamic mechanisms remain controversial. We calculated receiver functions (1748) from Global Seismographic Network seismic stations TLY and ULN and stacked receiver functions in different bins. Here we present discontinuities at depths of 410km and 660km and thickness of the mantle transition zone (MTZ) beneath the study area. The MTZ structure shows an obvious thickening (292km) in the Baikal rift zone except for an area of limited thinning (230km), whereas it is basically normal (250km) beneath the Mongolian area, to the southeast of the Baikal rift. Combining these results with previous findings, we propose that the large-scale thickening beneath the Baikal rift zone is likely to be caused by the Mesozoic collision between the Siberian Platform and the Mongolia-North China Block or magmatic intrusion into the lower crust, which would result in crust and lithosphere thickening. Thus, the lower crust becomes eclogitized and consequently detached into the deep mantle because of negative buoyancy. The detachment not only induces asthenosphere upwelling but also accelerates mantle convection of water detached from the subducted slab, which would increase mantle melting, while both processes promote the development of the rift. Our preliminary results indicate that the detachment and the consequent hot upwelling have an important influence on the development of the Baikal rift, and a small-scale mantle upwelling indicated by the located thinning may have destroyed the lithosphere and promoted this development.