Paleo-earthquake studies on the eastern section of the Kunlun fault

Roughly along the Animaqing Maji peak, the Kunlun fault section between the Tuosuo Lake and Kendingna (east Maqin) can be subdivided into two geometric segments: the Huashixia and the Maqin segments. These two segments behave differently in their Holocene slip rates and paleo-earthquake activities, with obviously higher paleo-seismic activity on the Huashixia segment than on Maqin segment. As many as four strong Holocene earthquakes are identified on the Huashixia segment from trenching and geomorphic studies. The recurrent interval for the latest three earthquakes are at about 500 a and 640 a, respectively. On the Maqin segment, at least three paleo-earthquake events can be defined from trenching, with a recurrent interval for the latest two events at about 1000 a. M = 7.5 earthquakes on Huashixia segment recur at every 411 a to 608 a with a characteristic slip at 5.75±0.57 m. Although the Maqin segment is less active, its accumulated strain energy during the long time period since last earthquake occurred (about 1070 a BP) deserves enough notice on its future earthquake probabilities.