摘要
通过对地壳低速高导层和地震震源深度等有关资料的分析研究,在对地震发生前兆、特征及物理机制研究的基础上,初步提出了一个简单的地壳双层孕震模式:地壳存在有两层孕震结构,上层为主孕震层,是地震应力集中积聚和发震后释放应变能的地方,主要是岩石发生脆性变形层,深度在中上地壳范围内;下层为低速高导层,是诱发和加强上层脆性层岩石变形、应变能积累和破裂的主要因素之一,处于岩石脆—韧性变形的过渡带,强震的发生与本层有着密切的关系,深度在中下地壳范围内。同时基于该双层孕震假设讨论了强震的孕育环境及作用。
Through detailed analyses for available data concerning low-velocity and high conductive layer beneath the crust and seismic depths, based on the studying of seismic precursors, characteristics and physical mechanisms, a simple double-storey seismogenic hypothesis of the crust for continental strong shocks is preliminarily presented in this paper. The upper layer in mid-upper crust is main earthquake pregnant layer where stress concentrats and strain energy releases in earthquakes events, and is a brittle deformation layer of rocks. The lower one in mid-lower crust with high conductive and low velocity of P wave, is believed that it is one of the most important factors inducing and enhancing brittle deformation, strain energy cumulation and crack in the upper rocks. The latter layer locates in a transitional zone of rock deformation from brittle to ductile, which is closely associated with the occurrence of strong shocks. Meanwhile, seismogenic environment and significance for strong shocks based on the double-storey pattern are discussed in paper.
出处
《西北地震学报》
CSCD
北大核心
2006年第2期114-117,共4页
Northwestern Seismological Journal
基金
国家自然科学基金项目(40302029)
国土资源部区域地质调查项目(200413000007)
关键词
地壳双层模式
低速高导层
孕震机制
Double-storey pattern of the crust
Low-velocity and high conductive layer
Seismogenic mechanism
