论文部分内容阅读
本文根据近震源条件下,由北京数字遥测地震台网观测到的波形资料,利用Brune模式,得到了2002年1月至2006年6月期间首都圈及邻近地区989次ML≥2.0地震的震源谱,测定了它们的拐角频率和零频幅值。通过相关计算公式,得到了破裂半径、地震矩、地震能量、应力降、视应力等震源动力学参数。分析了这些动力学参数的标度关系以及在2006年7月4日河北文安MS5.1地震前的时空变化特征。结果表明,文安MS5.1地震前,视应力、应力降、地震能量与破裂半径比等出现了相对高值集中区,这些高值集中区主要分布在华北平原带上;从时间变化曲线可以看出,文安MS5.1地震前华北平原带上视应力、应力降、地震能量与破裂半径比等参数都表现出了明显的升高变化过程,而拐角频率则显示出趋势性下降变化特征。这可能与文安MS5.1地震前华北平原带上应力的增强过程有关。
Based on the waveform data from Beijing Digital Telemetric Seismic Network under near-source conditions and using the Brune model, the source spectra of 989 ML ≥ 2.0 earthquakes in the metropolitan area and adjacent areas from January 2002 to June 2006 were obtained. , Measured their corner frequency and zero frequency amplitude. Through the correlation calculation formula, the kinetic parameters such as rupture radius, seismic moment, seismic energy, stress drop and apparent stress were obtained. The scaling relations between these kinetic parameters and the spatio-temporal variations of the Wen-an-MS5.1 earthquake on July 4, 2006 were analyzed. The results show that before Wen’an MS5.1 earthquake, there are relatively high concentrated areas such as apparent stress, stress drop, seismic energy and rupture radius ratio. These high concentrated areas are mainly distributed in the North China Plain. From the time curve, Before the Wen’an MS5.1 earthquake, apparent stress, stress drop, seismic energy and rupture radius ratio of the North China Plain showed a markedly increasing process, while the corner frequency showed the trend of declining trend. This may be related to the enhancement of stress on the North China Plain before the Wen’an MS5.1 earthquake.