中国大陆地震条带统计特征分析   总被引：6，自引：0，他引：6       下载免费PDF全文

李莹甄  王海涛  邬成栋  王想  冯建刚  曲延军  王行舟 《地震学报》2011,33(5):568-581

对中国大陆具备相对完整资料的327次M≥5.0地震,分5个工作区进行了统一要求的地震条带图像扫描,发现96次中强震前存在条带图像,约占研究地震总数的29％.其中震前有条带地震与研究地震的比例分别为:华北地区30％,华东南区29％,川滇地区41％,青藏高原西北缘24％,新疆地区16 ％.中强震前出现条带比例最低的是新疆,...  相似文献   

Wave separation for the great Sumatra-Andaman earthquake with regional seismic array     

Chunyan Zhang  Sidao Ni  Key Lab of Intelligent Computing  Signal Processing of Ministry of Education  School of Mathematics  Anhui University  Hefei  China Key Laboratory of Dynamic Geodesy 《地震学报(英文版)》2011,(1):127-132

We analyzed the seismic waveforms from the December 26,2004 Sumatra-Andaman earthquake recorded at broadband seismic stations in western Europe.Previous studies involving of the beam-forming technique and high frequency analysis suggest that the earthquake ruptured with a duration of around 500 s.This very long duration makes P wave overlap with later arrivals such as PP wave,which follows P in about 200 s.Since P waves are crucial for modeling earthquake processes,we propose an iterative method to separate...  相似文献   

Textural and Geochemical Characteristics of Proglacial Sediments: A Case Study in the Foreland of the Nelson Ice Cap, Antarctica   总被引：1，自引：0，他引：1  

LIU Xiaodong  SUN Liguang  YIN XuebinInstitute of Polar Environment  University of Science  Technology of Chin  Hefei  Anhui 《《地质学报》英文版》2004,78(4):970-981

This paper presents a detailed study on the textural and geochemical characteristics of the proglacial sediments near the edge of modern Nelson Ice Cap, Antarctica. The grain size distributions of the proglacial sediments are characteristic of glacigenic deposits, but very different from those of aeolian and lacustrine sediments. Moreover, the grain size distributions of the proglacial sediments are fractal with a dimension of about 2.9, and the fractal dimensions can be used as another summary statistical parameter for quantifying the relative amounts of coarse and fine materials. Correlations between the absolute element abundances of the proglacial sediments are very weak due to mineral partitioning and other effects of glacial processes, but correlations between the element/Rb ratios are statistically significant. This finding indicates that element/Rb ratios can be used to reduce or eliminate the effects of glacial processes, evaluate geochemical data and determine the sediment provenance in the for  相似文献   

The Hybrid Nature of 0846＋51W1： a BL Lac Object with a Narrow Line Seyfert 1 Nucleus     

Hong-Yan Zhou  Ting-Gui Wang  Xiao-Bo Dong  Cheng Li  Xue-Guang ZhangCenter for Astrophysics  University of Science  Technology of China  Hefei   《中国天文和天体物理学报》2005,5(1):41-48

We found a NLS1 nucleus in the extensively studied eruptive BL Lac object, 0846+51W1, out of a large sample of NLS1s compiled from the spectroscopic dataset of SDSS DR1. Its optical spectrum can be well decomposed into three components: a power law component from the relativistic jet, a stellar component from the host galaxy, and a component from a typical NLS1 nucleus. The emission line properties of 0846+51W1, FWHM  相似文献   

K-H Instability of Dust Plasma     

Shi Zhi-dong  Li Zhong-yuanUniversity of Science  Technology of China  Hefei    PRC Advanced Centre for Earth Science  Astronomy  Third World Academy of Science 《紫金山天文台台刊》1996,(2)

Areview about K-H instability related to comet tail is presented.The effect of dust graing on KHI is theoretically analysed and relations of critical shear to excit KHI with the properties of dust grains both for sheared ion flow and for sheared dust flow re put out.Their possible application in comet tail is suggested.  相似文献   

腾冲火山区地表垂直形变分析   总被引：11，自引：3，他引：8  

胡亚轩  施行觉  王庆良  张永志  赵慈平  施发奇  邵德晟 《大地测量与地球动力学》2003,23(2):37-41

对腾冲火山区1998～2000年的3期垂直形变资料进行了分析，进而利用相关资料得出与计算有关的参数，再用多元Mogi模型反演了岩浆房的位置和大小，所得出的结果与地震层析反演结果基本相似。分析反演结果，认为火山区可能存在多个岩浆房，并有岩脉相通。  相似文献   

Chemical Composition of Ancient Celadon Material （1127-1279 A.D.） from Zhejiang, China and Its Implication     

PENG Zicheng LEUNG Po Lau YU Peter CHENG Peikai LI Mai 《《地质学报》英文版》2006,80(5):759-762

The microprobe EDXRF equipment was used for analysis of the major and trace elements in glaze layer-transitive layer-body layer of the celadon from the Altar Yao （Kiln） and Laohudong Yao in the Southern Song Dynasty （1127-1279 A.D.）, Zhejiang, China. The K values of the discriminant factor for the celadon wares are larger than 8, which means the celadon of the Altar Yao and Laohudong Yao are different from that of the Longquan Yao. The former two belong to the Guan Yao system （the Chinese imperial kilns）, but the latter to the Min Yao system （the Chinese popular kilns）. The principle component analysis shows their relationship between the Altar and Laohudong wares with provenance postulation. The thickness of the transitive layer in the Altar and Laohudong wares is obviously different, which reveals the microstructure characteristics of the celadon even though both kinds of wares belong to the imperial kiln system.  相似文献   

西藏羌塘西北部干枯沟地区早三叠世晚期碱性岩类的发现     

钟华明  童劲松  鲁如魁  夏军 《地质通报》2006,25(7):806-811

碱性花岗岩分布于西藏羌塘北部的花岗岩带内,岩石K2O Na2O含量达11.27%～12.02%,具高铝、高碱、低铁镁组分的特征,属碱性花岗岩类.地球化学特征表明,该碱性岩形成于后碰撞期.形成该岩体的物质主要来源于加厚陆壳的中下部,反映了研究区古特提斯闭合后经历了陆内造山阶段.霞石正长岩同位素锆石U-Pb年龄为248.7Ma±2.6Ma,相当于早三叠世晚期.碱性花岗岩的出现是西藏西北部古特提斯造山带崩塌开始的岩石学标志.  相似文献   

白云鄂博矿田碳酸岩墙年代学再研究   总被引：9，自引：0，他引：9  

刘玉龙  陈江峰  李惠民  肖国望  张台荣 《地质论评》2006,52(3):415-422

白云鄂博地区发育侵入于白云鄂博群的碳酸岩墙。碳酸岩墙(00BYC19)中锆石的SHRIMPU-Pb下交点年龄为1984±180Ma,其ID-TIMS上交点年龄为2085±330Ma。碳酸岩墙(02BY80)中锆石SHRIMP的上交点年龄为2035±51Ma;02BY81中锆石的ID-TIMS上交点年龄为1934±64Ma。主矿北碳酸岩墙(00BYC21)的全岩Pb-Pb等时线年龄为1236±300Ma。本文及前人对白云鄂博地区的碳酸岩墙的定年结果表明该地区碳酸岩墙至少有两个阶段的侵入事件,第一阶段在2.0Ga左右,第二阶段在1.2Ga左右。前者是白云鄂博地区以至阴山地块北缘的一次主要的构造—岩浆事件,标志白云鄂博裂谷和白云鄂博群地层的形成。第二阶段的碳酸岩墙,代表白云鄂博裂谷在中元古代的活化,且与成矿有密切关系。  相似文献   

SHRIMP U-Pb Zircon Age of the Ka''''erjiao Intrusion in the Sawur Region in West Junggar,Xinjiang          下载免费PDF全文

ZHOU Taofa  TAN Lugui  FAN Yu  YUAN Feng  YANG Wenping  HE Lixin  YUE Shucang School of Resources  Environmental Engineering  Hefei University of Technology  Hefei  Anhui No. Geological Party  Xinjiang Bureau of Geological Exploration  Altay  Xinjiang 《《地质学报》英文版》2007,(2)

Acid intrusions are widespread in the Sawur region, Xinjiang. The Ka'erjiao intrusion is mainly composed of albite granite porphyry, K-feldspar granite porphyry, ivernite and granite porphyry. Being a transitional product between magma intrusion and eruption in the Sawur region, the Ka'erjiao intrusion was formed at the telophase of the late Carboniferous to the begining of early Permian as determined by the SHRIMP U-Pb zircon dating, with an age of 302.6±7.6 Ma (1σ). The intrusion consists of alkali-enriched rock, whose REE distribution patterns are of the LREE enrichment type, theδEu value is low and Nd, Sr, Pb isotopes reflect its mantle source characteristics. Theδ18O value of intrusion is low as a result of isotope exchange with meteoric water. The geochemical characteristics show that it was formed in a post-collisional tectonic setting. Taking combined considerations of current studies of A-type granites and Permian volcanic rocks, we think that in the telophase of the late Carboniferous to the beginning of the early Permian, the Sawur region was within the extension or compressional to extensional period of a post-collisional stage. The Ka'erjiao intrusion from mantle sources can confirm the vertical continental crust growth in the late Paleozoic. The Sawur region in west Junggar is consistent with east Junggar in post-collisional tectonic evolution process.  相似文献