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991.
通过对盘锦部分地区的调查工作和地层情况总结,判断出盘锦地区地质灾害种类有砂土液化、软土触变、咸水入侵。为了减轻或避免地质灾害对工程安全的危害性及周边环境的影响,需对其采取防治措施。砂土液化应采取强夯、砂土挤密桩等措施;软土触变应采取石灰砂桩、旋喷或粉喷等深基础措施;咸水入侵应采取以防为主、控制开采的措施。 相似文献
992.
S. M. Saprygin 《Russian Journal of Pacific Geology》2008,2(2):158-164
Detailed seismic zoning of Sakhalin based on seismological, tectonic, geomorphological, hydrogeological, and other data is discussed. It is shown that strong crustal earthquakes occurred at the boundary between the Eurasian and Okhotsk plates and their recurrence in Central Sakhalin is equal to the duration of the tectonic cycle (75 years). This boundary in North Sakhalin is marked by the Upper-Piltun fault, which was the epicenter of the 1995 Neftegorsk earthquake with an intensity of 9. The analysis of paleosoils in the fault zone showed that such events repeat with an interval of 400 years. The development of large oil and gas reservoirs on the Sakhalin shelf will be accompanied by intensification of the seismicity, which can reach a magnitude of M = 6.0–6.5 in the Lunskoye field. 相似文献
993.
In order to examine the response of the tropical Pacific Walker circulation(PWC) to strong tropical volcanic eruptions(SVEs), we analyzed a three-member long-term simulation performed with Had CM3, and carried out four additional CAM4 experiments. We found that the PWC shows a significant interannual weakening after SVEs. The cooling effect from SVEs is able to cool the entire tropics. However, cooling over the Maritime Continent is stronger than that over the central-eastern tropical Pacific. Thus, non-uniform zonal temperature anomalies can be seen following SVEs. As a result, the sea level pressure gradient between the tropical Pacific and the Maritime Continent is reduced, which weakens trade winds over the tropical Pacific. Therefore, the PWC is weakened during this period. At the same time, due to the cooling subtropical and midlatitude Pacific, the Intertropical Convergence Zone(ITCZ) and South Pacific convergence zone(SPCZ) are weakened and shift to the equator. These changes also contribute to the weakened PWC. Meanwhile, through the positive Bjerknes feedback, weakened trade winds cause El Nino-like SST anomalies over the tropical Pacific, which in turn further influence the PWC. Therefore, the PWC significantly weakens after SVEs. The CAM4 experiments further confirm the influences from surface cooling over the Maritime Continent and subtropical/midlatitude Pacific on the PWC. Moreover, they indicate that the stronger cooling over the Maritime Continent plays a dominant role in weakening the PWC after SVEs. In the observations,a weakened PWC and a related El Nino-like SST pattern can be found following SVEs. 相似文献
994.
强台风“黑格比”暴雨洪涝特征及成因分析 总被引:3,自引:0,他引:3
利用NCEP/NCAR再分析资料,分析0814号强台风"黑格比"引发华南西南部严重暴雨洪涝特征及其成因.结果显示:①2008年9月下旬副高强度偏强,位置偏北偏西,台风易受其南侧偏东气流引导而西行;②台风"黑格比"强度强,辐合上升运动强烈,触发强降雨;③南海夏季风增强和季风辐合带北抬,西南暖湿气流强盛,增强了辐合上升运动,并为台风降雨带来了源源不断的水汽,使降雨加强和持续;④除了气象因素外,地形对西行台风降雨量的显著增幅作用,是造成强台风"黑格比"暴雨洪涝的重要原因. 相似文献
995.
四川3次7级以上地震序列和余震分布特征的对比 总被引:1,自引:0,他引:1
本文对比了汶川8.0级、炉霍7.6级和松潘、平武7.2级地震的地震序列类型、余震分布形状及其阶段性特征,并分析了这些特征异同与发震断裂带的特性关系。主要结论有:(1)扩大川滇其他震例对比统计认为,位于活动地块边界的大型活动断裂带上的强震往往是主震—余震型,双震或震群型地震往往不在块体边界大断裂带上。(2)强震余震区形状和余震随时间分布的阶段性受发震断裂带组合方式制约。 相似文献
996.
利用近场数字强震记录资料,采用和达法、台网地震编目程序(BLOC86)分别对新疆乌恰、伽师地区4次中强地震进行了重新定位.通过对定位结果的对比分析,结合新疆台网的部分实际工作,认为充分利用近场数字强震资料参与定位对于提高、总结和研究新疆部分地区地震定位精度是很有必要的. 相似文献
997.
The reason for the failure to forecast the Wenchuan M_S8.0 earthquake is under study, based on the systematically collection of the seismicity anomalies and their analysis results from annual earthquake tendency forecasts between the 2001 Western Kunlun Mountains Pass M_S8.1 earthquake and the 2008 Wenchuan M_S8.0 earthquake. The results show that the earthquake tendency estimation of Chinese Mainland is for strong earthquakes to occur in the active stage, and that there is still potential for the occurrence of a M_S8.0 large earthquake in Chinese Mainland after the 2001 Western Kunlun Mountains Pass earthquake. However the phenomena that many large earthquakes occurred around Chinese Mainland, and the 6-year long quietude of M_S7.0 earthquake and an obvious quietude of M_S5.0 and M_S6.0 earthquakes during 2002~2007 led to the distinctly lower forecast estimation of earthquake tendency in Chinese Mainland after 2006. The middle part in the north-south seismic belt has been designated a seismic risk area of strong earthquake in recent years, but, the estimation of the risk degree in Southwestern China is insufficient after the Ning’er M_S6.4 earthquake in Yunnan in 2007. There are no records of earthquakes with M_S≥7.0 in the Longmenshan fault, which is one of reasons that this fault was not considered a seismic risk area of strong earthquakes in recent years. 相似文献
998.
Wanzheng Cheng Zhiwei Zhang Xiang Ruan Earthquake Prediction Institute Earthquake Administration of Sichuan Province Chengdu China 《地震学报(英文版)》2009,(2):109-117
Based on abundant aftershock sequence data of the Wenchuan MS8.0 earthquake on May 12, 2008, we studied the spatio-temporal variation process and segmentation rupture characteristic.Dense aftershocks distribute along Longmenshan central fault zone of NE direction and form a narrow strip with the length of 325 km and the depth between several and 40 km.The depth profile(section of NW direction) vertical to the strike of aftershock zone(NE direction) shows anisomer-ous wedgy distribution characteristic of aft... 相似文献
999.
1000.