The 2008 Hotan Earthquake: Tectonic Setting and Regional Seismicity

On 20 March 2008 at 22:32 UTC, a magnitude 7.2 earthquake struck 226 km southeast of Hotan in Xinjiang Uyghur Autonomous Region, China. The event occurred at a shallow depth of 10 km. According to records of strong earthquakes since 1 January 2000, this remains the sole M7.2 event in the immediate area. The Hotan region lies along the southern margin of the Tarim Basin, where the ongoing collision between the Indian and Eurasian plates drives active deformation. Convergence rates of approximately 40–50 mm per year are accommodated by thrust and strike-slip fault systems, including structures linked to the Kunlun and Altyn Tagh fault zones. The shallow focal depth is consistent with brittle failure in the upper crust of this compressional regime. Geological mapping indicates that the epicentral area features Paleozoic sedimentary sequences overlying Precambrian basement, deformed by Cenozoic thrusting. Historical seismicity in western Xinjiang reflects this tectonic framework, with events typically associated with reactivation of inherited faults. The 2008 earthquake fits this pattern, occurring within a zone of elevated strain accumulation south of the Tarim craton. Post-event studies have refined understanding of rupture characteristics, though the event produced limited surface rupture owing to its depth and local geology. No subsequent M7+ earthquakes have been recorded in the immediate vicinity through the present.

References

USGS Earthquake Catalog (event data and regional seismicity since 2000) China Earthquake Administration reports on Xinjiang tectonics