Structural analysis and interpretation of the surface deformation associated with the Ning’er,Yunnan Province,China <Emphasis Type="Italic">M</Emphasis><Subscript>S</Subscript>6.4 earthquake of June 3, 2007     

杨晓平  陈立春  马文涛  陈慧  周挚  李岩峰  谢英情  施伟华  常祖峰 《地震科学（英文版）》2008,21(2):170-180

The seismogenic fault and the dynamic mechanism of the Ning’er, Yunnan Province M_S6.4 earthquake of June 3, 2007 are studied on the basis of the observation data of the surface fissures, sand blow and water eruption, landslide and collapse associated with the earthquake, incorporating with the data of geologic structures, focal mechanism solutions and aftershock distribution for the earthquake area. The observation of the surface fissures reveals that the Banhai segment of the NW-trending Ning’er fault is dominated by right-lateral strike-slip, while the NNE-trending fault is dominated by left-lateral strike-slip. The seismo-geologic hazards are concentrated mainly within a 330°-extending zone of 13.5 km in length and 4 km in width. The major axis of the isoseismal is also oriented in 330° direction, and the major axis of the seismic intensity VIII area is 13.5 km long. The focal mechanism solutions indicate that the NW-trending nodal plane of the Ning’er M_S6.4 earthquake is dominated by right-lateral slip, while the NE-trending nodal plane is dominated by left-lateral slip. The preferred distribution orientation of the aftershocks of M_S≥2 is 330°, and the focal depths are within the range of 3～12 km, predominantly within 3～10 km. The distribution of the aftershocks is consistent with the distribution zone of the seismo-geologic hazards. All the above-mentioned data indicate that the Banhai segment of the Ning’er fault is the seismogenic fault of this earthquake. Moreover, the driving force of the Ning’er earthquake is discussed in the light of the active block theory. It is believed that the northward pushing of the Indian plate has caused the eastward slipping of the Qinghai-Tibetan Plateau, which has been transformed into the southeastern-southernward squeezing of the southwest Yunnan region. As a result, the NW-trending faults in the vicinity of the Ning’er area are dominated by right-lateral strike-slip, while the NE-trending faults are dominated by left-lateral strike-slip. This tectonic framework might be the main cause of the frequent occurrence of M_S6.0～6.9 earthquakes in the area.  相似文献   

缢蛏群体微卫星分析中样本量对遗传多样性指标的影响   总被引：2，自引：0，他引：2       下载免费PDF全文

牛东红  陈慧  林国文  李家乐 《海洋科学进展》2010,28(2)

采用微卫星标记进行缢蛏(Sinonovacula constricta)群体遗传研究时,群体的样本量多少对遗传多样性指标准确性有影响。实验设置了11个样本量梯度,并对观测等位基因数(Na),有效等位基因数(Ne),表观杂合度(Ho),期望杂合度(He)和Nei’s遗传多样性指数(H)的变化趋势进行了分析。结果表明,样本量与观测等位基因数和有效等位基因数具有高度的正相关性,与杂合度和内氏遗传多样性指数呈中度相关。当样本量小于20时,遗传多样性指标均呈现迅速增加的趋势;当样本量大于30,杂合度和内氏遗传多样性指数趋于稳定。建议在利用微卫星进行群体遗传结构评估时,最适参数为期望杂合度和内氏遗传多样性指数,最小样本量为30。  相似文献