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朱元清 《地震地磁观测与研究》1989,10(3):27-32
上海电信传输地震台网现有地面和深井观测点13处。本文根据现有的台站布局导出了估算震中定位误差的统计模型。计算了它的最大监测能力及其定位精度。结果表明上海台网至少有4个台站可同时记录到上海市内M_L≥1.5和网内M_L≥2.0的地震,并且网内的震中定位水平误差大约为2km。 相似文献
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张宏志 《地震地磁观测与研究》1988,(2)
本文利用有效观测范围的估算,b值检验,震中分布检验法对北京电信传输地震台网的实际监测能力进行了计算和分析,得出了北京台网对网内最小地震的检测能力与对网外地震的控制范围。然后利用实际观测资料讨论震中误差和震级偏差。 相似文献
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本文通过天津遥测地震台网在华北遥测地震台网联网后的监控能力的计算和对1992年1—10月地震观测报告的分析处理,得到了一些主要结果。首先,台网的控制能力为:以天津市为中心,半经30km范围内,震级下限为M_L2.0,天津地区及邻区20km内震级下限为M_L2.5。其次,台网的定位精度百分比为:震中误差小于15km的占88％,震中误差15—30km的占8％,震中误差30km的占4％,若以全国地震月报目录定的震中位置为准,天津定的震中位置与其误差小于15km的占81.4％。同时我们还对不同震级,不同震中距(以天津市为中心)的地震的定位精度进行了统计,统计结果为距天津200km范围内的地震,震中误差在15km以内的占91.4％,而距离天津300km以上的地震,震中误差大于30km的占70％。这表明天津台网对远距离地震定位精度较差,这是因为对远距离的地震,天津台网的子台全集中在震中的一侧所致。 相似文献
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煤矿冲击矿压现象日益严峻,作为矿山动力灾害的主要监测手段,微震监测系统已在许多矿井广泛使用,为保证矿震定位和能量计算的准确,提高预测预报煤矿冲击矿压的可行性,应建立一套台网布设优化及评价系统.应用微震定位和D值优化设计理论,结合煤矿实际条件研究了影响矿震定位精度的主要因素和不利条件,并提出了采用综合指数法确定煤矿高微震活动区域和区域内矿震发生的概率,制定了台站候选点和监测区域确定的一般原则.通过理论分析震中和震源标准差反映台网定位能力的不足,建立基于数值仿真实验方法的震中与震源误差期望值模型,最终形成台网布设优化及评价系统.实验和现场应用结果表明,该系统能够快速确定台网最优布设方案,准确评价台网定位能力,满足煤矿微震监测的需要. 相似文献
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新建成的首都圈数字地震台网由 10 7个数字地震台站组成 ,其地震监测和定位能力需要检验。此文主要目的是为评估首都圈数字地震台网的地震活动监测能力提供参考依据。在地震定位中 ,应充分发挥数字地震记录的优势 ,采用相应的数字地震记录处理技术 ,提高地震定位的可靠性和精度。采用滤波、偏振及台站扫描、震相追踪等数字技术 ,提高了震相识别的可靠性和精度 ,并用Geiger方法对 2 0 0 1年首都圈数字地震台网记录到的 7个网内及网缘微震 (ML<2 .0 )进行了精确定位 ,还通过对爆破的定位来检验程序和方法的可靠性和精度。结果表明 ,震中定位误差估计小于2km ,震源深度误差估计小于 3km 相似文献
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叙述了1989年12月25日侯马市发生4.9Ms地震前距震中约100km的赵城观测站地应力出现的异常情况,指出只要埋设环境、安装方法、观测程序符合规范要求,简易地应力对一定范围内的较大地震是有监测能力的。 相似文献
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介绍了上海地震台阵观测系统，该观测系统是由地震台阵、佘山数据中心、上海信息中心等部分组成，对各部分的功能及设备系统结构作了较为翔实的分析，并简要描述了台阵数据处理软件系统。上海地震台阵投入并网运行后表明，从根本上改善了地震波形、特别是远震波形的记录，并从总体下提出了上海地震台网的地震综合监测能力。 相似文献
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采用基于概率的完整性震级（PMC）方法,选取上海测震台网13个地震台站及周边省市地震台2008-2019年记录的171个地震,计算各地震台及上海测震台网地震监测能力,并模拟增加新的地震台站后台网监测能力的变化。结果显示：①地表基岩台的监测能力较深井台强,且受噪声和地铁影响,市区深井台监测能力较低;②整体上,台站密布的松江和青浦地区,地震监测能力较强,最小完整性震级为ML 0.7。台站稀疏的浦东、奉贤、崇明地区,地震监测能力较弱,最小完整性震级为ML 1.3;③若在上海南部增设奉贤海湾台,可整体提高上海测震台网的监测能力。 相似文献
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上海市自1998年开始开展了利用GPS技术监测地面沉降的研究,先后进行了可行性论证、GPS基准网建设、数据处理和平差方法的探索等一系列课题的研究,并布设了由34点组成的覆盖整个上海市的地面沉降监测基准网.为了进一步提高基准网的监测精度和沉降监测的时空分辨率,于2004年又布设了4个24小时连续运行的GPS固定站,对上海市地面沉降实施连续监测.为了考查GPS沉降监测的大地高可能达到的精度,研究合理的观测纲要与数据处理方案,本文在介绍并总结了上海市地面沉降GPS监测工作的同时,分析了GPS沉降监测基准网前后6期的观测数据.数据分析采用GAMIT/GLOBK软件包和GPS_NET软件,计算结果表明,在基线边长达到30～40km时,GPS在大地高方向上的中误差仍可控制在2mm左右,由此推算GPS监测地面沉降的分辨率在3mm左右,完全能够满足上海市地面沉降监测的需要. 相似文献
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地磁转换函数在上海及邻近地区地震预报中的应用 总被引：2，自引：0，他引：2
汪江田 《地震地磁观测与研究》1998,19(6):6-11
地磁转换函数的变化已被广泛用于中短期地震预报。本文利用佘山地震台１９７７￣１９９６年和崇明地震台１９８３￣１９９６年的地磁短周期资料处理所得的转换函数变化,监视跟踪上海及邻近地区地震活动。通过几次中强地震震例的总结,提出用地磁转换函数方法来预报上海及其邻近地区地震的一些判断。用此方法,曾较好地预报过１９９０年常熟５．１级地震和１９９６年长江口以东海中６．１级地震。 相似文献
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Lake Taihu, the third largest fresh water lake in China, with a surface area of 2 338 km2, is located in the Changjiang River Delta, the most advanced economic zone in China. During the last two decades, the rapid economic development of local agriculture and industry both in the urban and rural areas of the region has made great advances. Great quantieis of pollutants have been discharged into the lake, its nutrient content has increased continuously, and phytoplankton blooms have occurred in some areas. Water quality protection in Lake Taihu is very important because of its close relation with economical development and people''s daily life. It is urgent to have comprehensive pollution control in Lake Taihu. Based on water quality monitoring data in Lake Taihu from 1987 to 1994, the dynamic variations of water quality and eutrophication trends have been analyzed, showing obvious spatial and temporal variations. The main water quality factors were compared with the standard for drinking water and indicate considerable change with the seasons. Some basic strategies to protect water quality and prevent eutrophication are discussed. 相似文献
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Spatio-temporal exploratory analysis of urban surface temperature field in Shanghai, China 总被引：1，自引：0，他引：1
Xiaoyan Dai Zhongyang Guo Liquan Zhang Dan Li 《Stochastic Environmental Research and Risk Assessment (SERRA)》2010,24(2):247-257
The integrated application of remote sensing, geographic information system and quantitative analytical modeling can provide
scientific and effective methods for monitoring and studying urban heat island, based on land surface temperature (LST) retrieved
from thermal infrared channel data of sensors. In this paper, LST is retrieved from Landsat TM6 and ETM + 6 data of Shanghai
central city in 1989, 1997, 2000 and 2002, by using the mono-window algorithm. Based on the data, global and local spatial
autocorrelation analysis, and geostatistical methods are adopted to quantitatively describe the characteristics of spatial
heterogeneity and temporal evolution of land surface thermal landscape at different scales and periods in Shanghai central
city, by utilizing exploratory spatial data analysis. Results show that LST field in Shanghai central city tends to fragmentize
and complicate with the development of Shanghai, and its global spatial difference becomes greater gradually. The spatial
variance pattern of the change of LST field from 1997 to 2002 indicates that the dynamic change of LST presents a tendency
of increase in circularity. LST declines distinctly in the districts of Puxi and Pudong near and inside the inner ring road,
while it rises obviously outside the central city and near the out ring road. The extrema of temporal change in LST field
have a characteristic of spatial clustering. Besides, as the city of Shanghai expands in a circular pattern as a whole, the
directional difference of dynamic change of urban surface thermal landscape exists but is not very obvious. 相似文献
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Marathwada Agricultural University, Pharbani, has developed about 560 hectares of Wagarwadi watershed in Pharbani district since 1987. Groundwater monitoring on 16 observations wells at weekly intervals commenced in January 1992, and rainfall and pan evaporation has been measured daily at a hydrometeorological station situated in the nearby university campus. Aquifer parameters, namely, transmissivity and specific yield, have been estimated by carrying out a pumping test on a large diameter well. Groundwater recharge resulting from rainfall has been estimated using a water balance model of the soil moisture zone considering soil zone thickness and crops grown. The SCS (Soil Conservation Service) curve number method was used for surface runoff estimation. The groundwater flow model has been constructed using the nested squares, finite difference method. Nested square meshes of sizes 160 m×160 m and 80 m×80 m have been used and the steady-state condition of aquifer system was simulated in the model assuming the June 1992 water level configuration under equilibrium conditions. The model has been calibrated for transient conditions incorporating additional seepage from the water harvesting structures and their contribution to the groundwater regime has been assessed. © 1998 John Wiley & Sons, Ltd. 相似文献
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Geotomographic imaging in the study of mining induced seismicity 总被引：1，自引：0，他引：1
R. P. Young D. A. Hutchins J. McGaughey J. Towers D. Jansen M. Bostock 《Pure and Applied Geophysics》1989,129(3-4):571-596
Geotomographic imaging is a technique which allows seismic waves to be used to gain information about the internal structure of rock masses, in a way conceptually similar to medical CAT scanning. Traditional approaches to the study of mining-induced seismic phenomena have concentrated on using passive monitoring methods. This paper gives an overview of the developments in the acquisition, processing and interpretation of geotomographic data and outlines how images can be used in conjunction with passive techniques to study mining-induced seismicity.Presented at the Fred Leighton Memorial Workshop on Mining Induced Seismicity, Montreal 1987. 相似文献
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Using the equations of ozone transport and measurements of the vertical ozone distribution and atmospheric parameters above Seva (1987–1988) and Amundsen-Scott (1987) stations, the vernal ozone destruction has been calculated for the cited periods. The values of chlorine and bromine oxides have been estimated. It has been indicated that a rather high ozone destruction was observed in 1987 above Seva and Amundsen-Scott stations, which was caused by high concentrations of ClO and BrO. In 1988, the temperatures at levels of 14–16 km were increased to 210–220 K, and ozone destruction was less pronounced and was caused by the meridional transport of ClO and BrO form the inner Antarctic regions due to the ingression of the Australian anticyclone on the Antarctic continent. 相似文献
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乌鲁木齐地区近期垂直形变特征探讨 总被引：2，自引：2，他引：2
通过数理统计、拟稳平差等方法对乌鲁木齐地区的三期水准测量成果作了综合处理,绘制了1971—1980年、1980—1987年、1971—1987年乌鲁木齐地区现代垂直形变图,并讨论了乌鲁木齐地区现代垂直形变场的演变特征。 相似文献