Reply to the discussion by Olsen and Stuedlein on “Use of terrestrial laser scanning for the characterization of retrogressive landslides in sensitive clay and rotational landslides in river banks”Appears in Canadian Geotechnical Journal, 47(10): 1164–1168.

In their discussion about aerial laser scanning (ALS) and terrestrial laser scanning (TLS), Olsen and Stuedlein present some issues than we did not address in our paper (Jaboyedoff et al. 2009a). Our study deals with compact landslide bodies and we had to overcome many related problems, such as shadowing, vegetation, site accessibility, and safety issues. In contrast, Olsen and Stuedlein deal with linear, clean features (coastal cliffs), which enable a completely different way of working. Nonetheless, their remarks are relevant and they were not addressed in our paper because it was beyond the scope of our study. Studies on landslide volumes and mechanisms do not in general need a high accuracy, while it is crucial for landslide movement monitoring. In their discussion, Olsen and Stuedlein give some examples of TLS applications in landslide studies in addition to those highlighted in our article. Most of them relate to coastal erosion and rockfalls in cliffs, and only a few relate to landslides. For the sake of completeness of the literature overview, TLS has also been widely used for

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