鄂尔多斯活动地块边界带15000年以来强震活动与现今大地震空区
摘要
<p indent="0mm">The active block theory was introduced into intracontinental earthquake research that strong continental earthquakes are controlled by the movement and deformation of active block. This theory is very important for understanding strong earthquake occurrence and related mechanisms far away from the plate boundaries, and also provides conceptual framework for short- and long-term prediction of strong earthquakes on the continents. The boundary zones of active blocks composed of different types of active structures is the potential risk areas where strong earthquakes occur, which have been proved by the occurrences of modern earthquakes in recent years. With respects to this correlation between the occurrence of strong earthquake among different active tectonics, a comprehensive study is needed to focus on the faults related to strong earthquake but also the associated active block. Here we summarized long-term strong earthquake activities in the boundary zones and characteristics of the active blocks, and provides more complete estimates on future risk areas around the Ordos block. The Ordos Block, situated in the central part of the mainland of China, represents a typical active block surrounded by diverse active tectonic zones. As one of the most significant seismically active regions in the mainland of China, the Ordos Block has experienced over 50 strong earthquakes with magnitudes (<italic>M</italic>) ≥ 6.5 according to historical records. Notably, the vicinity of the block has experienced over 5 large earthquakes with <italic>M</italic> ≥ 8. Due to the dynamic effect of the Tibetan Plateau and the Pacific Plate, the Ordos block has significant strong earthquake, leading to distinct fault systems with varying characteristics of movement, zoning, and segmentation along its boundary zones. In total, we recovered 180 strong earthquake events from the main fault zones around the Ordos active block and recovered the different structural zones in the bo