基于岩浆凝固的地壳动力学研究  

Crustal Dynamics Based on Magma Solidification

作　　者：霍睿智 贺端威[1,2] HUO Ruizhi;HE Duanwei(Institute of Atomic and Molecular Physics,Sichuan University,Chengdu 610065,China;Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学原子与分子物理研究所,四川成都610065 [2]四川大学高能量密度物理教育部重点实验室,四川成都610065

出　　处：《高压物理学报》2018年第5期31-39,共9页Chinese Journal of High Pressure Physics

基　　金：中国工程物理院中子物理学重点实验室课题(2014AB01);国家自然科学基金(51472171;11427810)

摘　　要：地球在形成之初处于熔融状态,随着时间的推移,地球表面的岩浆不断冷却、凝固,发展成现在的圈层结构,并且地球物质的冷却及液-固转变依然在持续。通过对地震发生后地球日长变化进行统计分析,发现总体上地震后地球自转速率加快。分析认为,这一现象是由于地幔部分岩浆冷却凝固使地壳岩石圈下部体积塌缩所致。由此,建立了一个地壳动力学模型,以解释地壳各板块间的相互作用和相对运动,并且认为地震等地质活动的动力学成因主要是地球内部熔体持续凝固所导致的地壳下部体积收缩、压力减小,在重力作用下,构成地壳的各板块之间的相互作用加剧,原有力学结构失稳,发生大规模岩层错位、断裂,从而引起地震、火山爆发等剧烈的地质活动。通过建立热学模型和力学模型,验证了上述观点。The earth was in a molten state at the beginning of its formation.Over time,the magma on the earth s surface began to cool down and solidify,and the earth has gradually become such a trap structure.However,the cooling and liquid-solid transformation process of the earth materials continues until today.This paper presents a statistical analysis of the change of earth s length-of-day after earthquakes,and it is found that the earth s rotation speed is generally accelerated after great earthquakes.We believe that this phenomenon is caused by the cooling and solidification of the magma in the part of the mantle,which causes significant volume collapse of the lower crustal lithosphere.Thus,we set up a crustal dynamic model to explain the interaction and relative motion of tectonic plates.We believe that the dynamic genesis of earthquake and other geological activities are due to the continuous solidification of the melt in the interior of the earth which could lead to a volume shrinkage and pressure drop in the lower part of the earth s crust.The effect of gravity enhances the interaction among tectonic plates,the original mechanical structure becomes unstable,and eventually the massive rock fracture occurs,which can cause severe geological events such as earthquakes,and volcanic eruptions.This conclusion has been further validated based on the thermal and mechanical model proposed in this paper.

关 键 词：地壳动力学 岩浆凝固 地震机制 日长 

分 类 号：P65[天文地球—地质学] P553