汶川地震对湖北地震活动趋势的影响

5·12汶川地震之前的3年多时间里,湖北境内及周边依次发生了九江Ms5.7、随州帆4.7、荆州帆4.2和竹山帆4.6等一系列中等强度地震,地震活动的频度和强度均明显高于近几十年的平均水平,在湖北历史地震中这种情况也不多见,在时间上又恰好发生在汶川地震之前.本文通过大地构造背景、历史地震活动、汶川地震前后湖北地震活动情况分析和震源机制解等方面探讨了近几年湖北地震活动与汶川地震的关系.     

Temporal variations of <Emphasis Type="Italic">δ</Emphasis><Superscript>18</Superscript>O of atmospheric water vapor at Delingha

Oxygen stable isotope of atmospheric water vapor is widely used to study the modern process of climate. Atmospheric water vapor samples were collected at Dlingha, northeast of Tibetan Plateau during the period from July 2005 to February 2006. The variation of δ ¹⁸O and the relationships between δ ¹⁸O and both the temperature and specific humidity are analyzed in this paper. Results show that the seasonal variation of δ ¹⁸O of atmospheric water vapor at Delingha is remarkable with higher δ ¹⁸O in summer and lower δ ¹⁸O in winter. The temporal variation of vapor δ ¹⁸O shows obvious fluctuations, with magnitude of over 37‰ The daily variation of the δ ¹⁸O is highly correlated with air temperature. The relationship between δ ¹⁸O and atmospheric water vapor content is complex. Study shows that δ ¹⁸O of atmospheric water vapor is positively correlated with specific humidity in winter in seasonal scale and inversely correlated with specific humidity in summer rainy period. The δ ¹⁸O values of atmospheric water vapor are lower than those of precipitation at Delingha, and the average difference is 10.7‰ Variations of δ ¹⁸O of atmospheric water vapor is also found to be affected by precipitation events, The model results show that the precipitation effect could have caused the vapor δ ¹⁸O in the raining season to lower by 7% in average in July and August. Supported by the National Natural Science Foundation of China (Grant Nos. 40671043, 40571039 and 40771048) and National Basic Research Program of China (Grant No. 2005CB422002)     

中国东部史前地震事件的的识别问题

中国东部地区气候湿润,物理化学风化作用强烈,加上地震周期长,人类活动频繁,地质事件遗迹难寻;另一方面,东部地区经济蓬勃发展,建(构)筑物和公众地震安全要求攀升.本文为解决这一日益尖锐矛盾作了相应综述和分析,并提出了一些建议:从经验预报统计样本局限性分析入手,综述史前地震识别标志和事件时序的分析研究现状,在此基础上提出了中国东部地区史前地震事件强化研究思路,即充分利用大规模考古发掘和工程所揭露的机遇,抢救性编录、分析.同时与考古、地质等相关部门联手,反演并重构全新世以来天然变形事件时序,用于弥补经验性预报的样本局限,从而科学预测地震趋势.作者的初步实践表明,这一思路是可行的,通过持之以恒的努力,有望达到预期目标.     

扎龙湿地自然保护区的火灾管理

通过对黑龙江省扎龙湿地自然保护区自然资源状况和火灾特点的分析,结合当地社会经济及环境中存在的问题,为研究地区的林火管理提出具体建议。研究表明,在防火季节,有效地控制火源,提高当地居民的防火意识是预防火灾的关键;此外,保证保护区水源供应在火灾预防中起着关键作用。研究结果可为湿地类型自然保护区的林火管理提供参考。     

当前地震应急管理宣传教育对策研究

我国突发公共事件应急管理宣传教育工作日益受到重视,但目前仍处于相对落后的水平,比如地震。主要表现为：应急管理的宣传教育流于宣传,教育基本空白;应急管理的宣传教育体系尚不完善、制度尚不健全;高质量的应急宣传教育门户网站尚未建立等。针对存在的这些问题,以浙江省为例,提出今后改进地震应急管理宣传教育工作的一些建议和对策。     

佘山地震台防雷技术研究与应用

在详细分析雷电灾害特征的基础上,阐述了防雷工作的主要技术手段。并针对地震台站的构成特点,研究了台站综合防雷系统的设计方法和技术措施。同时,以余山地震台为例,具体说明了防雷措施的应用方法及应用效果。     

“十五”测震台网数据库的应用程序开发

通过介绍地震数据查询和分析处理软件的编程经验,简要阐述了基于“十五”测震台网数据库客户端应用程序的开发思路。“十五”测震台网Jopens系统数据库,为开发Windows环境下的地震数据分析处理软件提供了良好的在线数据资源,借助MySql ODBC驱动程序开发Mysql客户端软件不失为一种较好的方法。     

丹东形变观测洞室改造

“十五”期间,为了新增水管仪、伸缩仪,丹东地震台对形变观测洞室进行了环境改造,新建了仪器基墩,解决了建造仪器基墩过程中遇到的施工难题,为水管仪和伸缩仪运行提供了良好的观测条件。文中介绍的方法对其他台站建造仪器基墩有一定借鉴意义。     

天水地磁台不同组合绝对观测系统精度研究

选取对天水地磁台两套不同组合绝对观测系统的观测数据,进行数据处理,探讨其观测精度与差异.通过对基线值的对比分析知,DIF组合比DFZ组合观测精度高,性能稳定.说明DI仪观测精度相对较高,尤其是D的观测优势明显,且F墩差很容易测量和归算.在处理过程中,利用计算机自动由"实测值"计算得到"采用值",在保证精度的前提下,工作效率显著提高.同时,为适应数字化观测积累经验,做好观测系统换代的准备工作,本文对如何提高地磁观测资料质量的方法做了细致的总结.     

Reconstruction of paleocoastlines for the northwestern South China Sea since the Last Glacial Maximum

The range of relative sea level rise in the northwestern South China Sea since the Last Glacial Maximum was over 100 m. As a result, lowland regions including the Northeast Vietnam coast, Beibu Gulf, and South China coast experienced an evolution from land to sea. Based on the principle of reconstructing paleogeography and using recent digital elevation model, relative sea level curves, and sediment accumulation data, this paper presents a series of paleogeographic scenarios back to 20 cal. ka BP for the northwestern South China Sea. The scenarios demonstrate the entire process of coastline changes for the area of interest. During the late glacial period from 20 to 15 cal. ka BP, coastline slowly retreated, causing a land loss of only 1×10⁴ km², and thus the land-sea distribution remained nearly unchanged. Later in 15–10 cal. ka BP coastline rapidly retreated and area of land loss was up to 24×10⁴km², causing lowlands around Northeast Vietnam and South China soon to be underwater. Coastline retreat continued quite rapidly during the early Holocene. From 10 to 6 cal. ka BP land area had decreased by 9×10⁴km², and during that process the Qiongzhou Strait completely opened up. Since the mid Holocene, main controls on coastline change are from vertical crustal movements and sedimentation. Transgression was surpassed by regression, resulting in a land accretion of about 10×10⁴km². Supported by Key Laboratory of Marginal Sea Geology, Chinese Academy of Sciences (Grant No. MSGL0711), the Guangdong Natural Science Foundation (Grant No. 04001309) and Open Fund of the Key Laboratory of Marine Geology and Environment, Chinese Academy of Sciences (Grant No. MGE2007KG04)