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龙陵地震是由7个相对独立的次级序列组成的强震群,除了两次大震(M7.3,7.4)之外,还发生了M≥6的强震5次。 龙陵地震序列的主要成分发生在被三条大断裂包围的三角形断块内部。发震构造是由一系列规模不大的断层组成的“断层带”,这是一种新生的、处于崛起过程中的活构造,强震的发生是断层发展、连贯过程的体现。发震构造是由北北西—南北向和北东—北东东向的“断层带”交切而成的构造格架,在北北东向的主压应力场作用下,地震活动过程显示了突出的共轭性构造活动。 整个龙陵序列没有一条规模较大的构造统一控制,7个次级序列的主震有各自的破裂面,这些破裂面对震区地震活动的控制能力很低,说明龙陵地震的脆性“碎裂”特征。龙陵序列的主要成分发生在花岗岩基上,花岗岩的相对各向均一性是“碎裂”特征的物性基础。
The Longling earthquake is a strong earthquake swarm composed of seven relatively independent secondary sequences. In addition to two large earthquakes (M7.3 and 7.4), a strong earthquake with M≥6 occurred five times. The main component of the Longling earthquake sequence occurs within the triangular fault block surrounded by three major faults. Seismogenic structure is a “fault zone” composed of a series of small faults. It is a new and active structure in the process of rising. The occurrence of strong earthquakes is the embodiment of fault development and coherence. The seismogenic structure is a tectonic framework intersected by “North-South-West-North-South and North-East-North East-East” fault zones. Under the action of the north-north-east main compressive stress field, the seismogenic process shows that Prominent conjugative tectonic activity. The whole Longling sequence does not have a unified control over the larger structures. The main shocks of the seven secondary sequences have their own rupture planes. These rupture planes have very low control over the seismic activity in the earthquake zone, indicating that the fragile “crushing” of the Longling earthquake Split “feature. The main component of the Longling sequence occurs on granite basement, and the relative homogeneity of granite is the physical basis of the ”fragmentation" feature.