Abstract: The hypothesis that strong earthquakes in China mainland are controlled by the movement and interaction of active-tectonic blocks was advanced by Chinese scientists, with the remarkable ability to encompass geological and geophysical observations. Application of the active-tectonic block concept can illustrate 6 active-tectonic block regions and 22 active-tectonic blocks in mainland China and its neighboring regions. Systems of active-tectonic block boundaries are characterized by a zone of decades or hundreds of strong earthquakes. One of the greatest strengths of the modern active-tectonic block hypothesis is its ability to explain the origin of virtually all the M8 and 80% M7 earthquakes on the main continent in eastern Asia. In other words, active-tectonic block boundary stands in strong causal interrelation with recurrence behaviors of strong earthquakes and thus, it is possible to predict an earthquake occurrence in principle. After nearly two decades of development and improvement, the active-tectonic block hypothesis has established its theoretical foundation for the active tectonics and earthquake prediction, and is promoting the transition from probabilistic prediction to physical prediction of strong earthquakes. The active-tectonic block concept was tested by application to a well-documented, high-frequent earthquake area, and was found to be an effective way of describing and interpreting the focal mechanism and seismogenic environment, but there are still many problems existing in the active-tectonic block hypothesis, which confronts with rigorous challenges. Future progress will continue to be heavily dependent on the high-precision synthetic seismogram, especially of critical poorly documented settings. It is well known that strong earthquakes occur anywhere in the interactions among the active-tectonic block boundaries where there is sufficient stored elastic strain energy driving fault propagation, and then releasing the stored energy. Therefore, future studies will focus on the mechanism and forecast of the strong earthquake activity in the active-tectonic block boundary zone, with fault activity within the active-tectonic block boundary zone, quantifying current crustal strain status, upper crust and deep lithosphere coupling relation, strong earthquake-generating process and its precursory variation mechanism in seismic geophysical model as the main research contents, which are the key issues regarding deepening the theory of active-tectonic block and developing continental tectonics and dynamics in the modern earth science.

Key words: China mainland, active-tectonic block, active boundary zone, tectonic characteristics, strong earthquake activity

摘要： 由中国科学家提出的 “中国大陆强震受控于活动地块运动与变形”的假说, 不仅可用于解释中国大陆强震的空间分布, 同时基于其理论和定义可将中国大陆划分为6个Ⅰ级活动地块和22个Ⅱ级活动地块。 活动地块之间的边界带往往由活动构造带组成, 一般宽约几km至百余km, 是强烈地震的多发区。 活动地块假说指出, 已发生的近100%的8级以上强震、 约80%的7级以上强震震中均位于地块边界带上。 近年来, 中国大陆几次7级以上强震也都发生在活动地块边界带, 这不仅验证了活动地块假说的理论模型, 同时还预测了未来强震就发生在活动地块边界带内某些有利于应力集中的部位。 活动地块假说经过近20a的发展, 已建立并逐步完善了其理论框架, 奠定了中国活动构造与强震预测的理论基础, 正推动着强震预测由概率预测向物理预测过渡。 但就活动地块的概念和理论框架而言, 还存在的诸多问题需进一步回答和解释。 众所周知, 强震是活动地块边界带特殊构造部位应变逐渐积累、 介质突发失稳和能量释放的结果, 地震预测的突破性进展需要建立在充分理解其整个物理过程的基础之上。 因此, 以边界带断裂的活动性、 现今的变形状态、 深浅构造的耦合关系、 强震孕育环境及震源物理模型为主要研究内容, 开展针对活动地块边界带强震活动机理与预测的研究, 是活动地块理论完善和研究未来关注的重要内容和重要科学问题。

关键词: 中国大陆, 活动地块, 边界带, 构造特征, 强震活动