内蒙古西部苦楚乌拉—英巴地区花岗岩锆石U-Pb定年及地球化学特征          下载免费PDF全文

赵闯  苏旭亮  薛斌  程东江  史兴俊  宋涛涛  张阔 《中国地质》2021,48(1):189-206

锆石U?Pb定年结果表明,内蒙古西部苦楚乌拉—英巴地区花岗岩包括晚泥盆世二长花岗岩((371±2)Ma)、中二叠世钾长花岗岩((271±1)~(270±1)Ma)和早白垩世二长花岗岩((133±1)Ma)。结合前人资料,将研究区晚古生代以来的酸性岩浆活动分为4期:晚泥盆世(~371 Ma)、晚石炭世(313~311 Ma)、早—中二叠世(282~270 Ma)和早白垩世(133~130 Ma)。地球化学组成上,晚泥盆世二长花岗岩属于非典型的S型花岗岩,反映了一种后碰撞的构造背景,一方面说明珠斯楞—杭乌苏构造带在石炭纪之前已经开始出现岩浆活动,另一方面可能也恰好反映了哈萨克斯坦+塔里木+华北板块与西伯利亚板块拼合时间的下限;中二叠世钾长花岗岩则属A型花岗岩,反映了地壳伸展减薄的构造背景,与同时期区域强烈的拉张构造背景具有良好的对应关系;早白垩世二长花岗岩与晚泥盆世二长花岗岩具有相似的地球化学特征,同样反映了一种后碰撞的构造背景,与同时期区域后碰撞的拉张构造背景一致。  相似文献   

Impact of FORMOSAT-3/COSMIC GPS radio occultation and dropwindsonde data on regional model predictions during the 2007 Mei-yu season     

Fang-Ching Chien  Ying-Hwa Kuo 《GPS Solutions》2010,14(1):51-63

A study of the impact of FORMOSAT-3/COSMIC GPS radio occultation (RO) and dropwindsonde data on regional model simulations for a 11-day period during the 2007 Mei-yu season is presented. The Weather Research and Forecasting (WRF) model and its three-dimensional variation component, WRF-Var, are used for regional model predictions of heavy rainfall events in Taiwan. Without the use of GPS RO and dropwindsonde data, pressure and relative humidity are, in general, underestimated by the model; temperature predictions have a warm bias at the low level and a cold bias at the high level; and the east–west and north–south component winds have positive and negative biases, respectively. Incorporating GPS RO data tends to improve the prediction for longer integration. The assimilation of dropwindsonde data improves the forecast at the earlier time and at higher levels, and the improvement decreases over time. The reason the dropwindsonde data produce a positive impact earlier and the GPS RO data later is that there are few GPS RO observations in the fine domain. The large-scale simulation is first improved using the GPS RO observations, and the resulting changes can have a positive impact on the mesoscale at the later time. The dropwindsonde observations were taken inside the fine domain such that their impact can be detected early in the simulation. With both types of observation included, the prediction shows even greater improvement. At the earlier forecast time, there is nearly no impact from GPS and dropwindsonde data on rainfall forecasts. However, at the later integration time, the GPS data start to significantly improve the rainfall forecast. The dropwindsonde data also provide a positive impact on rainfall forecasts, but it is not as significant as that of the GPS data.  相似文献   

Assimilation and Simulation of Typhoon Rusa （2002） Using the WRF System   总被引：7，自引：2，他引：5  

GU Jianfeng  Qingnong XIAO  Ying-Hwa KUO  Dale M. BARKER  XUE Jishan  MA Xiaoxing 《大气科学进展》2005,22(3):415-427

Using the recently developed Weather Research and Forecasting (WRF) 3DVAR and the WRF model, numerical experiments are conducted for the initialization and simulation of typhoon Rusa (2002).The observational data used in the WRF 3DVAR are conventional Global Telecommunications System (GTS) data and Korean Automatic Weather Station (AWS) surface observations. The Background Error Statistics (BES) via the National Meteorological Center (NMC) method has two different resolutions, that is, a 210-km horizontal grid space from the NCEP global model and a 10-km horizontal resolution from Korean operational forecasts. To improve the performance of the WRF simulation initialized from the WRF 3DVAR analyses, the scale-lengths used in the horizontal background error covariances via recursive filter are tuned in terms of the WRF 3DVAR control variables, streamfunction, velocity potential, unbalanced pressure and specific humidity. The experiments with respect to different background error statistics and different observational data indicate that the subsequent 24-h the WRF model forecasts of typhoon Rusa‘s track and precipitation are significantly impacted upon the initial fields. Assimilation of the AWS data with the tuned background error statistics obtains improved predictions of the typhoon track and its precipitation.  相似文献   

地球自转与El Nio——海气耦合理论     

刘式适  蒋循  刘式达  李黎明  王彰贵 《地球物理学报》2001,(4)

从低纬的海气耦合的浅水模式方程组出发 ,运用正交模和特殊函数的方法进一步讨论地球自转速率变化对海气耦合系统的影响 .研究表明 :地球自转速率的变化通过海气耦合一方面使大气和海洋的Kelvin波和Rossby波的移动及稳定性发生变化 ,另一方面使纬向风、洋流和海表温度发生变化 .特别是在地球自转减慢时 ,通过海气耦合 ,出现纬向风和洋流异常和大洋东部海表温度增加 ,从而导致引起全球气候异常的ElNi no现象  相似文献   

用两个台上的S波位移求震源地方岩体錯动的方向          下载免费PDF全文

郭增建 《地球物理学报》1960,9(1):20-24

这种方法的基本根据是:（一）震源地方岩体錯动的方向与横波离源时的方向、横波离源时的射綫方向在一个平面內;（二）横波在传播过程中,β角变化很小. 推导了由S波β角求横波离源时位移方向的公式.由两个台上的S波β角就可分別求得两个横波离源时的位移面,这两个面的交綫就是震源地方岩体錯动的方向。討論了在烏尔夫网上具体运用这一方法的作图.这就大大地簡化了求解的过程,便于大量处理数据。  相似文献   

用两个地震台的S波位移求震源地方岩体錯动的方向（续）          下载免费PDF全文

郭增建 《地球物理学报》1961,10(1):36-38

本文对求震源地方错动的方向提出了一个极简单的图解方法.所用的资料是两个台上的横波偏振角β.并讨论了在某些震中距离上对β角进行校正的问题.  相似文献   

震源孕育模式的初步讨论   总被引：34，自引：1，他引：34       下载免费PDF全文

郭增建  秦保燕  徐文耀  汤泉 《地球物理学报》1973,16(1):43-48

一、前言 地震发生时的模式,人们在震源机制研究中,已讨论很多了,而地震孕育模式则讨论很少。地震孕育模式直接关系着地震预报工作,所以本文想就这个问题作一些讨论。由于问题比较复杂,讨论仅限于单一断层带。构造交会区,有待以后探讨。  相似文献   

地震发生前的地下水位变化   总被引：3，自引：0，他引：3       下载免费PDF全文

郭增建 《地球物理学报》1964,13(3):223-226

本文列举了中国境內一系列大地震发生前地下水位发生变化的事实。这些事实說明了大地震发生前震中区的地层已有变形。  相似文献   

Preliminary Note on Quaternary Glaciation in Northeastern Yunnan     

C.C.YEH 《地质学报》1944,(Z1):128-138

正 With 1 Plate. INTRODUCTION During the last five years, evidence of Quaternary glaciation has been gathered by different geologists from Hupeh, Hunan, Kuangsi, and Sikang. H. von Wissmann, in his paper on the Pleistocene Glaciation in China, has made  相似文献   

Koeppen范式的中国气候区域     

涂长望  郭晓岚 《气象学报》1938,(2):51-67

著者在其“中国气候区域”一文中已详论过中国的气候及其分划,(气象研究所集刊第八号)但其目的纯为适应中国的需要和实用;对於不明瞭中国地理环境及名称的人则显得生疏而不易捉摸。为易於与世界其他各处的气候性质相比较及供不熟悉中国地名的人们的需要起见,爰乃根据Koeppen 氏的分类法将中国气候重新划分。 Koeppen氏在其“依照气温雨量及其年变化而分划气候区域”一文  相似文献