Advances and Overview on Researches of Active Tectonics in China

This paper briefly overviews major advance in researches of active tectonics of China. Initiation of active tectonic studies was characterized by descriptions of relations between faults and strong earthquakes during the 1920s to 1950s. Reconnaissance on active faults and fault-controlled Quaternary basins had been carried out along major historic seismic zones and in the regions where historic great earthquakes occurred during the 1960s to 1970s. Quantitative studies on active tectonics, including 1 : 50000 scaled mapping on major active structures, started from early 1980. Researches in this time period concentrated on fault geometry and segmentation, fault slip rates, active folds, earthquake surface ruptures and coseismic displacements, paleoearthquakes and earthquake recurrence intervals, relationships between surface and deep structures, delineation of crustal block and block motion, seismic hazard assessment and estimation of future amount of cosesimic displacement along a particular fault. Such parameters were obtained along more than 10 major fault zones in China. In general, slip rates are fast and paleoearthquake recurrent intervals are short in the Tibetan Plateau. In contrast, slip rates are slow and paleoearthquake recurrent intervals are long in the Xinjiang and North China blocks. The paper also discussed aspects that should be further studied with special emphasizes on active structures in the marginal sea regions.