论文部分内容阅读
北纬31°—35°、东经119°—125°范围内的南黄海地震区,中强地震活动频繁,这主要是由一组北北东向和北西—北西西向共轭走滑活动断层及张性铲形活动断层引起的,该区内的中强震活动具有准周期性,震中呈东移趋势,区内地震在原地或同一构造部位重复发生的概率比较高,且空间分布是不均匀的,其中,海域地震强度明显高于陆域地震,在第Ⅲ、Ⅳ地震活跃期内,中强震主要发生在北纬33°±1°、东经121°±1°所在的南黄海海域的南部盆地,本区第Ⅳ活跃期内中强地震的活动水平与近期内中小地震的活动水平相当,同时,海域地震还具有成丛性及57 年、6 年的节律,地震震中具有南北迁移的特征
The middle and strong earthquakes are frequent in the southern Yellow Sea seismic area within latitudes 31 ° -35 ° N and 119 ° -125 ° E, which is mainly caused by a series of north-north-east and northwest-north west-west conjugate strike-slip faults and Zhang Sexual activity of shovel-shaped faults. The moderate-strong earthquakes in this area are quasi-periodic and the epicenter moves eastwards. The probability of the earthquakes occurring repeatedly in situ or in the same tectonic part is relatively high and the spatial distribution is not uniform , In which the seismic intensity in the sea area is obviously higher than that in the land-based earthquake. During the active phases Ⅲ and Ⅳ, the moderate-strong earthquakes mainly occurred in the southern basin of the southern Yellow Sea where the latitude 33 ° ± 1 ° and the east longitude 121 ° ± 1 ° The activity level of moderate-strong earthquakes during the fourth active phase of this area is comparable with that of medium-small earthquakes in the near future. At the same time, the earthquakes in the sea area also have clumps and rhythms of 57 and 6 years, with the characteristics of north-south migration in epicenter epicenters