震后形变和岩石圈流变学结构  

Postseismic deformation and its association with lithospheric rheological structure

作　　者：刘绍卓 沈正康[2] 

机构地区：[1]中国地震局地质研究所地震动力学国家重点实验室,中国北京100029 [2]北京大学地球与空间科学学院,中国北京100871

出　　处：《地震学报》2014年第2期318-336,340,共19页Acta Seismologica Sinica

基　　金：自然科学基金重大项目(41090294)资助

摘　　要：岩石圈流变学结构是控制不同构造环境下岩石圈形变的关键因素之一.随着空间大地测量观测技术的发展,基于空间大地测量数据的震后形变研究对揭示断裂带内的力学性质和区域性岩石圈流变学结构已成为可能.该文首先基于岩石力学的摩擦和流变学实验,对余滑和分布式韧性流的构造物理背景进行了分别阐述,并介绍了震后形变数值模拟中本构关系和数值模型的发展.数值模型主要有解析、半解析和纯数值3类,涉及的本构关系包括基于速率-状态摩擦准则的余滑以及分布式韧性流中常用的线性流变学模型(麦克斯韦尔体和标准线性固体)和瞬态流变学模型(宏观经验性的伯格斯(Burgers)体和微观幂律流变律).然后以美国南加州1992年Landers MW7.3地震和1999年Hector Mine MW7.1地震震后形变研究为例,介绍了震后形变的研究进展.最后回顾了大陆岩石圈流变学结构的研究进展,并以震后形变研究中的流变学结构("三明治模型"和"焦糖布丁模型")存在的争议为例,说明了岩石圈流变学结构研究所具有的挑战性.Lithospheric rheological structure is a key factor in controlling litho- sphere deformation in different tectonic environments. With the development of space geodetic observation techniques in recent years, postseismic deformation studies based on space geodetic observations have been used to infer mechanicalproperties of fault zones and lithospheric rheological structure. Firstly, we introduce the tectonophysical background of afterslip and distributed ductile flow from the associated friction and rheological experiments, respectively, and summarize the developments of numerical models and constitutive laws for post- seismic deformation studies. The numerical models include analytical, semi-ana- lytical, and purely numerical models, whose constitutive laws involve rate-and- state friction afterslip, standard linear rheological models （e. g., Maxwell body and standard linear solid） and transient rheological models （e. g., macroscopic and empirically derived Burgers body and microscopic power-law flow） of dis- tributed ductile flow. Then, we review the development of postseismic deform- ation studies from case studies associated with the 1992 MwT. 3 Landers and 1999 Mw7. 1 Hector Mine earthquakes in southern California, USA. Finally, we review recent advances on the lithospheric rheological structure studies and show how challenging the studies on the lithospheric rheological structure are by the controversial Jelly Sandwich and Cr^me Brfil^fi rheological models in postseismic deformation studies.

关 键 词：震后形变 岩石力学 摩擦 流变 岩石圈流变学结构 

分 类 号：P315.725[天文地球—地震学]