GNGTS 2022 - Atti del 40° Convegno Nazionale

GNGTS 2022 Sessione 2.2 265 made of rock avalanche deposits. This resulted in a better resolution of the dam structure and thickness, and in a better definition of the bedrock depth. The bedrock is located below the gully streambed in the northwestern part of the landslide dam, while it nearly coincides with the gully streambed in the central and southeastern parts. Acknowledgements. Maury McSaveney from GNS Sciences (New Zealand) provided valuable insight into the Yang Jia Gou geology and rock avalanche features of the geological interpretation of the survey results. Figures were prepared by using the Generic Mapping Tools (GMT) software package (Wessel et al., 2019). References Bensen G.D., Ritzwoller M.H., Barmin M.P., Levshin A.L., Lin F., Moschetti M.P., Shapiro N.M. and Yang Y.; 2007: Processing seismic ambient noise data to obtain reliable brod-band surface wave dispersion measurements . Geophys. J. Int., 169, 1239– 1260. Bonnefoy-Claudet S., Cotton F. and Bard P.Y.; 2006: The nature of noise wavefield and its applications for site effects studies: a literature review . Earth Sci. Rev., 79, 205–227. Del Gaudio V.; 2017: Instantaneous polarization analysis of ambient noise recordings in site response investigations . Geophys. J. Int., 210, 443–464, doi: 10.1093/gji/ggx175. Del Gaudio V., Wasowski J., Hu W., Capone P., Venisti N. and Li Y.; 2021: Ambient noise and ERT data provide insights into the structure of co-seismic rock avalanche deposits in Sichuan (China) . Bull. Eng. Geol. Env., 80, 1-18, doi: 10.1007/s10064-021-02346-8. Derode A., Larose E., Campillo M. and Fink M.; 2003: How to estimate the Green’s function of a heterogeneous medium between two passive sensors? Application to acoustic waves . Applied Physics Letters, 83, 3054–3056, doi: 10.1063/1.1617373. Herrmann R.B.; 2013: Computer programs in seismology: An evolving tool for instruction and research . Seism. Res. Lettr., 84, 1081-1088, doi:10.1785/0220110096. Levshin A.L., Pisarenko V.F. and Pogrebinsky G.A.; 1972: On a frequency-time analysis of oscillations . Ann. Geophys., 28, 211-218. Li Y., Hu W., Wasowski J., Zheng Y. and McSaveney M.; 2021: Engineering geology. Rapid episodic erosion of a cohesionless landslide dam: insights from loss to scour of Yangjia Gully check dams and from fume experiments . Engineering geology, 280, 105971, doi: 10.1016/j.enggeo.2020.105971. Nakamura Y.; 1989: A method for dynamic characteristics estimation of subsurface using microtremor on the ground surface . Q Rep Railw Tech Res Inst, 30, 25–33. Snieder R.; 2004: Extracting the Green’s function from the correlation of coda waves: A derivation based on stationary phase . Phys. Rev. E. 69, 046610. Wapenaar K.; 2004: Retrieving the elastodynamic Green’s function of an arbitrary inhomogeneous medium by cross correlation . Phys. Rev. Lett., 93, 254301. Wasowski J., McSaveney M., Pisano L., Hu W. and Del Gaudio V.; 2021: Recurrent rock avalanches progressively dismantle a mountain ridge in Beichuan County, Sichuan, most recently in the 2008 Wenchuan earthquake . Geomorphology, 373, doi: 10. 1016/j.geomorph.2020.107492. Wathelet M.; 2005: Array recordings of ambient vibrations: surface-wave inversion . PhD thesis, Université de Liège, Belgium. Xu C., Yao X. and Dai F.; 2014: Three (nearly) complete inventories of landslides triggered by the May 12, 2008 Wenchuan Mw 7.9 earthquake of China and their spatial distribution statistical analysis . Landslides , 11, 441– 461, doi: 10.1007/ s10346-460013-0404-6.