Xianshuihe fault system

The Xianshuihe fault system is a major active sinistral (left-lateral) strike-slip fault zone in southwestern China, at the eastern edge of the Tibetan Plateau. It has been responsible for many major earthquakes, and is one of the most seismically active fault zones in this part of China.

Map of major active fault zones in the Tibetan Plateau

Tectonic settingEdit

The Xianshuihe fault system lies within the complex zone of continental collision between the Indian Plate and the Eurasian Plate. It forms one of a set of sinistral fault zones that help accommodate the eastward spreading of the Tibetan Plateau.[1] The fault zone defines the northern and eastern edges of the Sichuan-Yunnan block, and the southeastern boundary of the Bayan Har block.[2]

GeometryEdit

The Xianshuihe fault system comprises several distinct segments, with an overall length of about 350 km. The main segments are the Ganzi (or Ganzi-Yushu), the Xianshuihe, the Anninghe-Zemuhe, and the Xiaojiang faults.[3]

SeismicityEdit

Movements on this fault system have been responsible for many large historical earthquakes, with more than 20 events of magnitude greater than 6.5 since 1700.[4] Some of these earthquakes have formed linked sequences, with each event being triggered by the previous one due to stress changes.[5]

CreepEdit

Like the San Andreas Fault in California, the Xianshuihe exhibits a behavior called Aseismic creep. The Xianshuihe fault creeps at a rate of a few mm/yr between earthquakes.[6]

Notable earthquakesEdit

See alsoEdit

ReferencesEdit

  1. ^ Wang S., Fan C., Wang G. & Wang E. (2008). "Late Cenozoic deformation along the northwestern continuation of the Xianshuihe fault system, Eastern Tibetan Plateau" (PDF). Geological Society of America Bulletin. 120 (3–4): 312–327. doi:10.1130/B25833.1.CS1 maint: multiple names: authors list (link)
  2. ^ Xu, X.W.; Wen, X.Z.; Chen, G.H.; Yu, G.H. (2008). "Discovery of the Longriba Fault Zone in Eastern Bayan Har Block, China and its tectonic implication" (PDF). Science in China Series D: Earth Sciences. 51 (9): 1209–1223.
  3. ^ Kato N, Lei X & Wen X. (2007). "A synthetic seismicity model for the Xianshuihe fault, southwestern China: Simulation using a rate- and state-dependent friction law". Geophysical Journal International. 169 (1): 286–300. doi:10.1111/j.1365-246X.2006.03313.x.
  4. ^ Wang H., Wright T.J. & Biggs J. (2009). "Interseismic slip rate of the northwestern Xianshuihe fault from InSAR data" (PDF). Geophysical Research Letters. 36 (3). doi:10.1029/2008GL036560.
  5. ^ Zhang, Q.; Zhang P., Wang C., Wang Y. & Ellis M.A. (2003). "Earthquake triggering and delaying caused by fault interaction on Xianshuihe fault belt, southwestern China". Acta Seismologica Sinica. 16 (2): 156–165. Bibcode:2003AcSSn..16..156Z. doi:10.1007/s11589-003-0018-5.CS1 maint: multiple names: authors list (link)
  6. ^ Liu Guan-Zhong; Ma Jin; Zhang Hong-xu; Wang Jian-Jun; Yang Yong-Lin & Wang Lin (2013). "Study on activity features of Xianshuihe fault zone with fault creep and short baseline observation for the last 20 years". Chinese Journal of Geophysics- Chinese Edition. 56 (3). doi:10.6038/cjg20130317.