Critical links and development trends of research on active tectonics

Following a brief introduction of the general characteristics of active tectonics in China, this study analyzed two new features of large earthquakes with Ms ≥ 7 that have struck continental China since the beginning of the 21st century:(1) Large earthquakes occur primarily in clusters along the boundary fault zone of the Bayanhar active tectonic block-part of the Qinghai-Tibet active tectonic block; (2) Reverse fault-fold earthquakes have occurred multiple times within active basins or at basin-mountain boundaries. In response to the new seismic activity features and the new demand for disaster prevention and mitigation of engineering construction and the public, this study delved into the critical links or understudied aspects of research on active tectonics and explored the development trends and technical approaches for further strengthening related studies. First, research on active tectonics should highlight theoretical advancements and applications, including fine-scale research on the geometry of active faults. Furthermore, it is necessary to focus on the kinematics of active faults by combining their activity behavior with rupture segmentation and practically enhance the complementary study of paleoseismic trenches and offset microgeomorphic features. Most importantly, we should practically enhance the cross-disciplinary integration and applications of research on active tectonics with disciplines such as tectonic geomorphology, geophysical prospecting, crustal deformation, and seismology. Second, it is necessary to enhance research on regional active tectonics and the understanding of the cluster migration patterns and dynamic mechanisms of large earthquakes. The purpose is to elevate a holistic comprehension of large earthquake-related tectonic activity within active tectonic blocks and their boundary fault zones. To this end, we should organize and analyze the seismogenic structural environments and mechanisms of cluster earthquakes in active tectonic blocks across China. Furthermore, we should identify potential active or seismic structural zones susceptible to earthquake cluster activity by synthesizing detailed research findings from historical earthquakes and paleo-earthquakes. The aim is to provide scientific and technological support for dealing with the risks of violent earthquakes faced by potential seismic migration areas after major seismic activity in the Bayanhar active tectonic block. Third, particular attention should be directed toward under-studied aspects such as research on structures of reverse fault-fold earthquakes. Besides conventional techniques for research on active structures, it is necessary to examine the geomorphic deformation characteristics by combining tectonic geomorphology. Additionally, we should conduct deep seismic structure exploration and seismological studies. The purpose is to obtain deep structural features and comprehensively analyze the relationships between deep and shallow structures, construct deformation modes, and explore seismogenic mechanisms. Overall, we should focus on the above critical technical links and future development trends, thus providing a reference for in-depth research on active structures and disaster prevention and mitigation.