兰州盆地活断层的高分辨率浅层地震勘探技术

针对城市活断层浅层地震探测的一些技术问题,在兰州盆地的金城关断层和刘家堡断层沿线开展活断层浅层(50 m以内)地震勘探技术研究.主要采用纵波和横波多次覆盖共CMP点地震反射方法,获得了目标场地地震图像资料,尤其横波地震剖面更加清晰地反映出超浅层构造空间特征.以红艺村测线(HYC)和师范学校西测线(SFXX)为例,分析总结了数据采集、资料处理、剖面解释三方面浅层活断层地震探测的技术要点.结果可以为兰州市及类似复杂构造地区活断层地震调查提供技术参考.     

"地震可预测性合作研究"计划:现有成就和发展重点

“地震可预测性合作研究”(CSEP)计划是一个对地震预测模型和预测算法开展前瞻性评估的全球信息化基础设施平台。CSEP的目标旨在提高我们对地震可预测性的理解、推进预测模型的研发、检验关键科学假设及其预测能力,以及改进地震危险性评估水平。自2007年在美国加利福尼亚州成立以来,全球CSEP合作一直在不同的构造环境及全球范围内进行预测实验,目前在四大洲运行4个检验中心,根据预期数据自动、客观地评估模型。这些实验为可操作的地震预测系统和地震危险性模型提供了大量的结果,并为地震的可预测性提供了新的、有时是令人惊讶的见解,还拒绝了对模型的改进。CSEP还开展了评估地震动和危险性模型的初步研究。本文报告了CSEP十年来取得的部分成就,并提出了未来地震活动性优先考虑的事项。     

南半球气流的气候特征

依据几十年的船舶和陆基观测资料而得到的网格点上的平均地面地转风,来估算南半球月平均地面流线。在南半球已确认有4个年气流源地。在南半球冬季的7个月期间,澳大利亚是第5个气流源地区域。北半球的气流流到南半球(夏季)的热带辐合带处。在平均年份中,南半球空气来自上述4个年气流源地的占46％,太平洋贡献最大(20％),其次是印度洋(12％)、大西洋(9％)和南极洲(5％)。最常见的汇流带有4条。     

对流层高、低空急流的耦合和强对流风暴发展的关系

一、引言对流层高、低空急流的相互作用对于对流性风暴系统的发展很重要,这个概念是由福布什和米勒(Fawbush和Miller;1953,1954)提出来的。他们指出:伴随对流层中空强西风的冷、干平流和低空暖、湿舌迅速北伸,是深厚对流发展的有利条件。并且指出风向强烈顺转很可能增强对流,这样对流层中空的风向与低空湿舌轴线之间的夹角很大。彼得森(Petterssen,1956)和牛顿(Newton,1967)指出风随高度的顺转及其造成的高、低空急流轴线交叉点上温度和湿度差动平流与对流不稳定发展的关系。最大的对流不稳定发生在高、低空急流轴线趋于正交和平流强度最大的时候。关于对流层急流在强对流风暴发展中的作用,     

中国玛珥湖的时空分布与地质特征

自新生代以来 ,在亚洲东部大陆边缘的裂谷系和青藏高原内部及周边地区 ,火山活动频繁发生 ,形成大量火山和火山岩 ,在一些火山区还发育有大小不等、形态不一的玛珥湖 ,其中有的积水 ,有的干枯 ,它们集中分布于雷琼、东北、青藏高原等地区 ,跨越了热带、亚热带、温带和高寒地带。从中新世的山东山旺盆地 ,早更新世东北龙岗地区的龙湾 ,到雷琼地区中晚更新世的田洋、湖光岩等 ,几乎各个时代、各种类型的玛珥和玛珥湖都有 ,玛珥湖中的沉积物从几十米到一二百米厚度不等 ,记录了不同地区、不同时段气候环境演变的历史 ,对全球变化研究有着重要意义。     

Modelling the variation of demersal fish distribution in Yellow Sea under climate change

Climate change can affect fish individuals or schools, and consequently the fisheries. Studying future changes of fish distribution and abundance helps the scientific management of fisheries. The dynamic bioclimate envelope model(DBEM) was used to identify the “environmental preference profiles” of the studied species based on outputs from three Earth system models(ESMs). Changes in ocean conditions in climate change scenarios could be transformed by the model into those in relative abundance an...     

Highly Siderophile Elements (Re, Au and PGE) in Porphyry Deposits and Their Mantle Origins

Please refer to the attachment(s) for more details     

Galaxy formation in the reionization epoch as hinted by Wide Field Camera 3 observations of the Hubble Ultra Deep Field

We present a large sample of candidate galaxies at z ≈ 7-10,selected in the Hubble Ultra Deep Field using the new observations of the Wide Field Camera 3that was recently installed on the Hubble Space Telescope.Our sample is composed of 20 z850-dropouts(four new discoveries),15 Y105-dropouts(nine new discoveries)and 20 J125-dropouts(all new discoveries).The surface densities of the z850-dropouts are close to what was predicted by earlier studies,however,those of the Y105-and J125-dropouts are quite unexpected.While no Y105-or J125-dropouts have been found at AB < 28.0 mag,their surface densities seem to increase sharply at fainter levels.While some of these candidates seem to be close to foreground galaxies and thus could possibly be gravitationally lensed,the overall surface densities after excluding such cases are still much higher than what would be expected if the luminosity function does not evolve from z～7 to 10.Motivated by such steep increases,we tentatively propose a set of Schechter function parameters to describe the luminosity functions at z ≈ 8 and 10.As compared to their counterpart at z ≈ 7,here L*decreases by a factor demanded by the existing observations,they are allowed and seem to agree with the data better than other alternatives.If these luminosity functions are still valid beyond our current detection limit,this would imply a sudden emergence of a large number of low-luminosity galaxies when looking back in time to z ≈ 10,which,while seemingly exotic,would naturally fit in the picture of the cosmic hydrogen reionization.These early galaxies could easily account for the ionizing photon budget required by the reionization,and they would imply that the global star formation rate density might start from a very high value at z ≈ 10,rapidly reach the minimum at z ≈ 7,and start to rise again towards z ≈ 6.In this scenario,the majority of the stellar mass that the universe assembled through the reionization epoch seems still undetected by current observations at z ≈ 6.