On a more precise assessment of seismic hazards for the city of Ulaanbaatar, Mongolia

The recent geological, geophysical, and paleoseismic research of the Hustai, Emeelt, and Gunjiin active seismogenic faults in the vicinity of Ulaanbaatar provided evidence of prehistoric seismic events there. In particular, dislocations of two fault-forming paleo-earthquakes were revealed in the Gunjiin tectonic zone. The shocks occurred in the Late Pleistocene-Early Holocene. The presence of ruptures, initially identified by morphological characteristics, was proven by trenching studies and materials of geophysical profiles. The magnitudes of the ancient earthquakes are estimated to be 6.5–7.0. The obtained results provide grounds for reassessment of the possible level of seismic hazards for the territory of Ulaanbaatar to at least 8.