The Har-Us-Nuur fault corresponds to one of the longest (>500 km) strike-slip fault in
Mongolian Altai. Although the fault clearly affects Quaternary deposits, no major instrumental or historical
earthquake is associated to it and only a few morphotectonic and paleoseismological analyses have been
carried out to date. In this paper, we analyze a previously undescribed surface rupture in the southern section
of the Har-Us-Nuur fault along which we study a 20 km long section of it in detail. A morphotectonic
analysis yielded a minimum slip rate of 0.32 ± 0.04 mm.yr1 , while paleosismological investigations
suggest a mean recurrence interval of about 8.1 ± 3.4 kyr from the characterization of three surface rupturing
events that occurred over the past 23 kyr. These preliminary results suggest that the Har-Us-Nuur fault slip
rate is inframillimetric and therefore lower than previous published estimates. They also suggest that the
fault is able to produce major earthquakes (Mw ≥7.5) separated by very long period of quiescence.
| Type : | : | Oral |
| Thématiques | : | 1.7 Failles actives, regards croisés. Que nous apportent les approches multi-disciplinaires dans la compréhension des systèmes de failles (a-)sismiques ? |
| Mots-Clés | : | Mongolia / Altay / active fault / Har ; Us ; Nuur fault / slip rate / paleosesismology |
| PDF version | : |  PDF version |
