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1999年辽宁省岫岩5.4级地震的临震预报及其地震活动研究 总被引：3，自引：0，他引：3
１９９９年１１月２９日１２日１０分（北京时间）,中国辽宁省岫岩地区发生一次５．４级地震。这次地震前,在震区记录到丰富的中小地震活动,组成了完整的地震系列。该系列具有小震频度随时间增多,震级上升,ｂ值较低,地震位置集中和地震Ｐ波被动一致,将其判断为震前系列,并抓住了前震活动从密集突然变为相对平静这一大震即将发生的特征,作出了临震预报,于１１月２８日晚入震意见通报给辽宁省地震局有关部门。这次地震的预报 相似文献
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TwoMS4.5 earthquakes happened in Yongning, a county of Yinchuan in Ningxia on June 22, 2010 and November 20, 2012, which were both strongly felt in Yinchuan and its vicinities. In order to understand the seismogenic structure better, we collected the regional earthquake waveform data of Ningxia and nearby seismic networks. Locating main shocks and aftershocks distribution by Hyp2000 and inversing the focal mechanism and depth by TDMT, we got results as follows: for the June 22 earthquake, nodal plane Ⅰ: strike 208, dip 89, and rake -164; nodal plane Ⅱ: strike 117, dip 74, and rake -2. For the November 20 earthquake: nodal plane Ⅰ: strike 284, dip 79, and rake 12, nodal plane II strike 192, dip 79, and rake 169. By means of reference to Snoke method, it is known that the main fractures of the two earthquakes are both strike slip faults with NNE-trending and NNW-dipping, while the former has a small amount of tension component and the latter has a small amount of thrust component. And the moment magnitudes of them areMW4.5 andMW4.3. According to Hyp2000 location, TDMT moment tensor fitting error and sPn depth phases, we consider that the focal depths of the two earthquakes are 22km and 8km, both are shallow-focus ones. Though the epicenters of the two earthquakes are 13km apart from each other, the former one is deeper, the reason is that the November 20 earthquake was controlled by the major fault of Yinchuan Fault, while the June 22 earthquake was controlled by south branch of Yinchuan Fault. 相似文献
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The results of microbiological water quality monitoring in the Amur and Sungary rivers after a technogenic accident in Tzilin
province (China) in November 2005 are considered. Bioindication technique is used to show that various pollutants earlier
entered the Amur with the Sungari runoff: low-molecular volatile benzene derivatives entered from November 28 to December
2; naphthalene derivatives entered from November 29 to December 7; and nitrobenzene and high-molecular polyaromatic hydrocarbons
entered in December 15–23, 2005. The major portion of pollutants moved along the right bank. The most sensitive to the total
pollution by toxic substances were nitrifying bacteria, especially in bottom water layers. The Amur water in the zone of influence
of the Sungari was estimated to belong to the IV–V quality class and referred to the categories of “polluted” and “dirty.”
The poor quality of Amur water persisted over 9 months throughout the Amur reach from the Sungari mouth to Khabarovsk City. 相似文献
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Sheshov V. Apostolska R. Bozinovski Z. Vitanova M. Stojanoski B. Edip K. Bogdanovic A. Salic R. Jekic G. Zafirov T. Zlateski A. Chapragoski G. Tomic D. Zurovski A. Trajchevski J. Markovski I. 《Bulletin of Earthquake Engineering》2022,20(2):795-817
Bulletin of Earthquake Engineering - At 03:56 local time on November 26, 2019, an earthquake with a Mw = 6.4 struck western part of Albania. The duration of the tremor lasted less than... 相似文献
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1999年11月29日,北京时间12点10分39秒(04:10:39 UTC)在我国辽宁海城-岫岩地区发生了一次Ms5.4地震.这次地震是继1975年2月4日海城Ms7.3地震之后该地区发生的震级最大的一次地震.区域性的辽宁数字地震台网记录了这一序列的前震、主震与 余震.本文运用该台网的记录资料,用双差法对海城-岫岩地... 相似文献
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目的:与DSA结果进行对照,评价MSCTA对心律不齐患者冠脉病变的诊断价值.方法:收集2009年1月至2010年11月在煤炭总医院临床诊断和怀疑冠心病的心律不齐患者31例,在一个月内分别完成MSCT和DSA检查.以DSA为参考标准,评价MSCTA在心律不齐患者中冠脉病变的诊断价值.结果:30例图像(96.77%,30/... 相似文献
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自1975年以来,海城附近发生具有一定规模和强度的震群（ML≥4．0;震次≥100次）有：1975年2月4日海城7．3级、1999年11月29日岫岩5．4级、2008年11月14日海城Ml4．8和2012年2月2日盖州Ml4．8震群,这4个震群发生前地震活动背景怎样,是否存在着某种共同的特点？对这4个震群进行对比研究发现：震前1年该区出现小震群活动,ML≥3．0地震条带、地震活动水平明显增强,连续发生多次ML≥4．0地震,ML≥4．0地震震源机制高度一致,且震中最近台站记录P波初动符号出现明显的一致性等变化,可视为地震异常。及时捕捉中强地震前异常,对于地震活动趋势判断起到至关重要的作用。 相似文献
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B. John Makario Londoño A. John Jairo Sanchez E. Luis Eduardo Toro Fernando Gil Cruz Olga Patricia Bohorquez 《Bulletin of Volcanology》1998,59(8):556-561
Coda Q–1 was calculated at Nevado del Ruiz Volcano (NRV) before and after two phreatomagmatic eruptions (November 1985, September
1989) and for a period of stability (May 1987) using a functional form for coda derived from a single scattering model (Sato
1977). Substantial changes were found before and after the eruptions. The highest value of Q–1 was found during the November 1985 eruption, an intermediate value for the September 1989 eruption, and the lowest value
for May 1987. It seems that the changes in coda Q–1 at NRV have a still-unknown relationship with the volume or magnitude of the eruption. A relatively strong frequency dependence
was found for all periods. Also Q–1 clearly changed with time, suggesting that the scattering was strong for the eruption of November 1985 and decreased for
the eruption of September 1989, and that the intrinsic absorption probably increased. This suggests the possibility that crystallization
is taking place in the NRV magma. The clear change of coda Q–1 before and after the eruptions at NRV also suggests the possibility that coda Q–1 is a premonitory tool of activity at this volcano.
Received: 25 October 1996 / Accepted: 21 January 1998 相似文献
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工作波长为532 nm的机载大气环境探测激光雷达AEDAL（Atmospheric Environment Detecting Airborne Lidar）装载在CMS_3807飞机上，于2005年11月7～11日期间在青岛地区及周边海域上空进行了飞行探测.此次实验的目的有两个：验证我国用于大气环境探测的激光雷达技术已经具备从地基向空基乃至天基发展的条件；获得青岛地区及周边海域边界层结构及大气气溶胶时空分布变化的特点.激光雷达的高时空分辨率为获取飞行路径上的边界层结构及气溶胶时空分布提供了可能.为了研究下垫面对边界层及气溶胶时空分布的影响，预定的飞行路径上包含了丰富的地形变化，有城市、丘陵、海区等.通过给出11月8日及11日的探测结果，不仅得到了不同地区边界层结构及气溶胶的时空分布特点，还可以看到冷锋、地形、地面气象场等因素对它们的影响. 相似文献
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1997年西藏玛尼7.5级地震2001年青海昆仑山口8.1级地震震前中长期预测 总被引：2，自引：3，他引：2
作者在1996年底对中国大陆2005年前6级以上强震危险区（13处）作出了预测，其中对应1997年玛尼7.5级地震、2001年昆仑山口8.1级地震，取得了很好的预报效果。本文分时段：1996年底前、1997年11月前、2001年11月前，分别总结了预测依据及震情跟踪分析。加上对同期（1997－2001年）其他强震预测的实际对应，表明地震活动图像分析方法在分析预报研究中是可以有所作为的。 相似文献
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The Kupaianaha vent, the source of the 48th episode of the 1983-to-present Pu'u 'O'o–Kupaianaha eruption, erupted nearly
continuously from July 1986 until February 1992. This investigation documents the geophysical and geologic monitoring of the
final 10 months of activity at the Kupaianaha vent. Detailed very low frequency (VLF) electromagnetic profiles across the
single lava tube transporting lava from the vent were used to determine the cross-sectional area of the molten lava within
the tube. Combined with measurements of lava velocity, these data provide an estimate of the lava output of Kupaianaha. In
addition, lava temperatures (calculated from analysis of quenched glass) and bulk-rock chemistry were obtained for samples
taken from the tube at the same site. The combined data set shows the lava flux from Kupaianaha vent declining linearly from
250 000 m3/day in April 1991 to 54 000 m3/day by November 1991. During that time surface breakouts of lava from weak points along the tube occurred progressively closer
to the vent, consistent with declining efficiency in lava transport. There were no significant changes in lava temperature
or in bulk MgO content during this period. Another eruptive episode (the 49th) began uprift of Kupaianaha on 8 November 1991
and erupted lava concurrently with Kupaianaha for 18 days. Lava flux from Kupaianaha decreased in response to this new episode,
but the response was delayed by approximately 1 day. After 14 November 1991, lava velocities were no longer measurable in
the tube because the lava stream beneath the skylight had crusted over; however, the VLF-derived electrical conductances documented
the decreasing flux of molten lava through the tube. Kupaianaha remained active, but output continued to decrease until early
February 1992 when the last active surface flows were seen. In November 1991 we used the linearly decreasing effusion rate
to accurately predict the date for the death of the Kupaianaha vent. The linear nature of the decline in lava tube conductance
and the delayed and slow response of the Waha'ula tube conductances to the 49th eruptive episode led us to speculate that
(a) the Kupaianaha vent shut down because of a decrease in driving pressure and not because of a freeze-up of the vent, and
(b) that Pu'u 'O'o, episode 49, and Kupaianaha were fed nearly vertically from a source deep within the rift zone.
Received: 29 September 1995 / Accepted: 21 November 1995 相似文献
13.
Three small-scale paroxysmal explosions (also called major explosions) interrupted ordinary mild Strombolian activity at Stromboli
on May 3, November 8 and 24, 2009. Products were largely confined to the summit area, except in the November 24 event, during
which coarse pumiceous lapilli reached the coast. Emission of crystal-poor pumice closely mingled with crystal-rich products
characterized the three events. The textural and chemical study of minerals and glassy matrices revealed that the two end-members
are mingled together physically in the May 3 and November 24 pumice, whereas November 8 products contain heterogeneous glass
with intermediate compositions derived from chemical mixing between crystal-rich and crystal-poor magmas. We here discuss
the different degrees of interaction between the two magmas in the three explosions in terms of magma dynamics during small-scale
paroxysms. 相似文献
14.
The tropical cyclones form over the oceanic regions where conventional meteorological observations are not available. This
contributes to a poor initial analysis of the cyclonic vortex and hence inadequate forecast. One way of overcoming the above
problem is to modify the initial analysis by replacing the weak and ill-defined vortex in the initial analysis with a synthetic
vortex having the correct size and intensity at the correct location. In this study we are investigating the effect of inclusion
of a synthetic vortex based on Rankine as well as on Holland wind profiles, using NCAR-AFWA bogussing scheme for the prediction
of four tropical cyclones, which formed over the Bay of Bengal during November 2002 and 2005, December 2005 and over the Arabian
Sea during May 2004, using the MM5 model. Two numerical experiments are designed in this study for each of the above four
cyclones. In the first experiment the model is integrated with a synthetic vortex based on Rankine wind profile while in the
second experiment we utilize the Holland wind profile. For the November 2002 cyclone, in both the experiments the model is
integrated from 10 November 2002 18 UTC to 12 November, 2002 12 UTC with the synthetic vortex inserted at the initial time.
The results of the study for the November 2002 cyclone show that the model simulation with the Holland vortex has produced
a stronger cyclone in terms of minimum sea-level pressure and maximum wind speed. Also, the results for the November 2002
cyclone with the Holland vortex showed a better longitudinal height section of the horizontal wind speed across the center
of the cyclone. The track error of the cyclone for the November 2002 cyclone is less in the model simulation with the Holland
vortex at the initial time and at 24 hours of forecast. The results for the November 2002 cyclone with the Rankine vortex
showed greater vertical wind speed as compared to the Holland vortex. However, for the November 2002 cyclone there were no
significant differences in the spatial distribution of precipitation for both the experiments. In order to provide an adequate
number of case studies for a good statistical sample, the present study is extended for three additional cyclones over the
Indian region. All four cyclones studied here show that the Holland vortex has produced a stronger cyclone in terms of the
minimum sea-level pressure and maximum wind speed. The Holland vortex showed a better vertical structure of wind speed in
the longitudinal height section at 24 hours of forecast for the November 2005 cyclone while the structure was better for the
Rankine vortex for the remaining two cyclones. There were no significant differences in the spatial distribution of precipitation
for the two experiments corresponding to all four cyclones. Some statistical results pertaining to all four cyclones are provided
such as the average track error as well as the average difference between the observed and the model minimum sea-level pressure
and the maximum wind speed. The statistical results corresponding to the average of all the four cyclones are at only a slight
variance with the results corresponding to the November 2002 cyclone. 相似文献
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2001年11月14日的昆仑山Ms8.1级地震前几天,中国地震台网多个台站都观测到了持续数天的低频震颤波信号.由于这些震颤波发生在强震前,所以备受关注.多年来研究人员对该震颤波的产生原因进行过多方探讨,但没有定论.该震颤波信号是否源自强震区的慢地震?是否是地震前兆?或为其它因素?为了回答这些问题,我们从多方面分析和研究了昆仑山强震前中国大陆宽频地震仪所观测的震颤波信号的特征、持续时间、震颤波强度变化与大规模大气运动的关系、信号强度随观测空间的衰减变化特征.结果表明:中国大陆宽频地震仪在昆仑山强震前观测到的震颤波由两个信号组成,其中11月10日开始出现,主要频率范围0.15~0.22 Hz (周期约4~7 s)、持续时间在10-13日的震颤波,主要由同时间段内发生在西太平洋的强台风玲玲(Ling Ling)引发;而11月11日开始出现,主要频率范围0.1~0.13 Hz (周期7~10 s)、持续时间在11-12日的震颤波,不是来自昆仑山强震区的慢地震,而是由来自欧洲北部及欧亚大陆的强温带气旋引发. 相似文献
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Pablo Samaniego Jean-Philippe Eissen Jean-Luc Le Pennec Claude Robin Minard L. Hall Patricia Mothes Deborah Chavrit Joseph Cotten 《Journal of Volcanology and Geothermal Research》2008
A petrological study of the eruptive products of El Reventador allowed us to infer the magmatic processes related to the 2002 and 2004–05 eruptions of this andesitic stratovolcano. On November 3, 2002, El Reventador experienced a highly explosive event, which was followed by emplacement of two lava flows in November–December 2002. Silica contents range from 62 to 58 wt.% SiO2 for the November 3 pyroclastic deposits to 58–56 and 54–53 wt.% SiO2 for the successive lava flows. In November 2004 eruptive activity resumed supplying four new lava flows (56–54 wt.% SiO2) between November 2004 and August 2005. 相似文献
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Michael A. Rasheed Kara R. Dew Len J. McKenzie Robert G. Coles Simon P. Kerville Stuart J. Campbell 《Continental Shelf Research》2008
Detailed data on seagrass distribution, abundance, growth rates and community structure information were collected at Orman Reefs in March 2004 to estimate the above-ground productivity and carbon assimilated by seagrass meadows. Seagrass meadows were re-examined in November 2004 for comparison at the seasonal extremes of seagrass abundance. Ten seagrass species were identified in the meadows on Orman Reefs. Extensive seagrass coverage was found in March (18,700 ha) and November (21,600 ha), with seagrass covering the majority of the intertidal reef-top areas and a large proportion of the subtidal areas examined. There were marked differences in seagrass above-ground biomass, distribution and species composition between the two surveys. Major changes between March and November included a substantial decline in biomass for intertidal meadows and an expansion in area of subtidal meadows. Changes were most likely a result of greater tidal exposure of intertidal meadows prior to November leading to desiccation and temperature-related stress. 相似文献
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Kaichi Maeda 《Pure and Applied Geophysics》1987,125(1):147-165
The global structures of annual oscillation (AO) and semiannual oscillation (SAO) of stratospheric ozone are examined by applying spherical harmonic analysis to the ozone data obtained from the Nimbus-7 solar backscattered UV-radiation (SBUV) measurements for the period November 1978 to October 1980. Significant features of the results are: (1) while the stratospheric ozone AO is prevalent only in the polar regions, the ozone SAO prevails both in the equatorial and polar stratospheres; (2) the vertical distribution of the equatorial ozone SAO has a broad maximum of the order of 0.5 (mixing ratio in g/g) and the maximum appears earlier at high altitude (shifting from May [and November] at 0.3 mb [60 km] to November [and May] at 40 mb); (3) above the 40 km level, the maximum of the polar ozone SAO shifts upward towards later phase with altitude with a rate of approximately 10 km/month in both hemispheres; (4) vertical distributions of the polar ozone AOs and SAOs show two peaks in amplitude with a minimum (nodal layer) in between and a rapid phase change with altitude takes place in the respective nodal layers; and (5) the heights of the ozone AO- and SAO-peaks decrease with latitude. The main part of AOs and SAOs of stratospheric ozone including hemispheric asymmetries is ascribable to: (i) temperature dependent ozone photochemistry in the upper stratosphere and mesosphere, (ii) variations of radiation field in the lower stratosphere affected by the annual cycle of solar illumination and temperature in the upper stratosphere and (iii) meridional ozone transport by dynamical processes in the lower stratosphere. 相似文献
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对云南地区地磁观测资料进行分析研究,总结了1986～2002年以来云南地磁场变化形态与异常特征。利用均方差、斜率、拟合等方法分析研究,以日均值为基础建立了一系列判定指标,获得发生在云南及邻区一些地震的震磁前兆信息。研究结果表明,云南地磁观测震前出现以下几种特征：1．短临加速变化异常;2．多台准同步异常;3．有一定形态过程的异常;4．破年变趋势异常。地磁异常以短临显示为多数,中期向短期过渡异常不明显。 相似文献