Airborne geophysical mapping as an innovative methodology for landslide investigation: evaluation of results from the Gschliefgraben landslide, Austria

Abstract

Abstract. In September 2009, a complex airborne geophysical survey was performed in the large landslide affected area of the Gschliefgraben valley, Upper Austria, in order to evaluate the applicability of this method for landslide detection and mapping. An evaluation of the results, including different remote-sensing and ground-based methods, proved that airborne geophysics, especially the airborne electromagnetic method, has a high potential for landslide investigation. This is due to its sensitivity to fluid and clay content and porosity, which are parameters showing characteristic values in landslide prone structures. Resistivity distributions in different depth levels as well as depth slices along selected profiles are presented and compared with ground geoelectrical profiles for the test area of Gschliefgraben.Further interesting results can be derived from the radiometric survey, whereas the naturally occurring radioisotopes 40 K and 232 Th, as well as the man-made nuclide 137 Cs have been considered. While the content of potassium and thorium in the shallow subsurface layer is expressively related to the lithological composition, the distribution of caesium is mainly determined by mass wasting processes.

Assessment of near-surface mapping capabilities by airborne transient electromagnetic data — An extensive comparison to conventional borehole data

“…Review papers by Dahlin (2001) for direct current (DC) methods and Tekzan (1999) and Everett (2012) for induction EM methods provide overviews of the large range of applications in which near-surface geologic information is useful. Among the most recent studies, one can find various applications such as aquifer vul-nerability mapping (Röttger et al, 2005), landslide hazards (Pfaffhuber et al, 2010;Supper et al, 2013), clay mapping (Donohue et al, 2012), agriculture regulation (Refsgaard et al, 2014), and overburden mapping Oluwafemi and Oladunjoye, 2013). Most of those studies rely on the mapping of clay geologic units because of their particular mechanical and hydraulic properties, which play key roles in geotechnical (e.g., landslides, construction) and hydrogeological (e.g., groundwater flow modeling, pollution plumes) problems.…”

Airborne Electromagnetics to Improve Landslide Knowledge in Tropical Volcanic Environments

“…Thus, it would be essential to verify low-resistance bodies located at approximately 5 Ω.m between a depth of 10 and 50 m. The two examples of the La Médaille landslide and the Morne-Figue area show that under landslides, some low resistivity formations could play the role of aquifers concentrating underground flows, punctually recharging the upper layers and influencing the activity of slope instabilities. The study of these bodies over the whole island, in correlation with recent hydrological studies [12,30] using AEM data, must be considered to better define this role on landslides [46]. It may be possible to refine the knowledge of unstable slopes from this information.…”

“…Airborne electromagnetics (AEM) provides information on lithology and regolith over large surfaces and/or hard-to-access areas [36][37][38][39][40]. It is able to provide plentiful pseudo-3D information about geological structures reaching a few hundred meters [41,42] and has been successfully used in many environmental studies [30,[43][44][45][46][47] particularly in volcanic settings. AEM is therefore useful to analyze the internal structure of large landslides [48][49][50][51].…”

Existence of subsurface structures from aeromagnetic data interpretation of the crustal architecture around Ibi, Middle Benue, Nigeria

“…The magnetic method is widely used for mapping important targets in mineral and hydrocarbon exploration projects [1][2][3], and data can be acquired in the air, on the ocean, from the ground, and in borehole, for a wide range of geological purposes [4]. Modern aeromagnetic survey is capable of mapping valuable geologic structures on a regional scale including concealed terrains due to the sophistication of modern technology to provide highquality data [5][6][7].…”