Coastal retreat is a non-recoverable phenomenon that—together with a relevant proneness to landslides—has economic, social and environmental impacts. Quantitative data on geological and geomorphologic features of such areas can help to predict and quantify the phenomena and to propose mitigation measures to reduce their impact. Coastal areas are often inaccessible for sampling and in situ surveys, in particular where steeply sloping cliffs are present. Uses and capability of infrared thermography (IRT) were reviewed, highlighting its suitability in geological and landslides hazard applications. Thanks to the high resolution of the cameras on the market, unmanned aerial vehicle-based IRT allows to acquire large amounts of data from inaccessible steep cliffs. Coupled structure-from-motion photogrammetry and coregistration of data can improve accuracy of IRT data. According to the strengths recognized in the reviewed literature, a three-step methodological approach to produce IRTs was proposed.

During the lowstand sea-level phase of the Last Glacial Maximum (LGM), a large part of the current Mediterranean continental shelf emerged. Erosional and depositional processes shaped the coastal strips, while inland areas were affected by aeolian and fluvial processes. Evidence of both the lowstand phase and the subsequent phases of eustatic sea level rise can be observed on the continental shelf of Sardinia (Italy), including submerged palaeo-shorelines and landforms, and indicators of relict coastal palaeo-environments. This paper shows the results of a high-resolution survey on the continental shelf off San Pietro Island (southwestern Sardinia). Multisensor and multiscale data—obtained by means of seismic sparker, sub-bottom profiler chirp, multibeam, side scan sonar, diving, and uncrewed aerial vehicles—made it possible to reconstruct the morphological features shaped during the LGM at depths between 125 and 135 m. In particular, tectonic controlled palaeo-cliffs affected by landslides, the mouth of a deep palaeo-valley fossilized by marine sediments and a palaeo-lagoon containing a peri-littoral thanatocenosis (18,983 ± 268 cal BP) were detected. The Younger Dryas palaeo-shorelines were reconstructed, highlighted by a very well preserved beachrock. The coastal paleo-landscape with lagoon-barrier systems and retro-littoral dunes frequented by the Mesolithic populations was reconstructed.

On the surface of the Moon a large number of linear features are recognizable. Long and narrow depressions are defined as lunar rilles. Their morphology has different characteristics, related to their origin. Among these, the sinuous rilles represent lineaments considered remnants of shallow lava channels. In this study, a quadrant of the Moon has been analyzed to recognize and map this type of morphology. An accurate morphometric analysis has been accomplished, using the Lunar Reconnaissance Orbiter Camera (LROC) which has a resolution of 100 m/pixel, and the Digital Elevation Model from Lunar Orbiter Laser Altimeter (LOLA) with a resolution of 6 m/pixel. Fifty-one sinuous rilles have been recognized in the study area, eighteen of which are new, improving a previous catalogue. The resulting quantitative and qualitative measurements were analyze and compared each other' to identify potential morphological trends. Different relationships between morphological parameters have been proposed, and the results enhance the importance of substrate composition in the evolution of these features, emerged mainly from the variations in width and depth values. The linear relationship between these two parameters is consistent with the idea that erosion efficiency acts proportionally in both vertical and horizontal directions. Partial filling phenomena by subsequent lava flows probably occurred in some sinuous rilles located in maria. The hypothesis of a constructive genesis requires further investigation to identify the levees created by sinuous rilles' formation process.

Connections between Plio-Pleistocenic tectonic activity and geomorphological evolution were studied in the Pardu Valley and Quirra Valley (Ogliastra, East Sardinia). The intensive Quaternary tectonic activity in Sardinia linked to the opening of the Tyrrhenian Basin is known. In Eastern Sardinia, it manifests with an uplift that is recorded by geomorphological indicators, such as deep-seated gravitational slope deformation, fluvial captures, engraved valleys, waterfalls, and heterogeneous water drainage. The Pardu River flows from the NW toward the SE and then abruptly changes direction toward the NE. At this point, a capture elbow adjacent to the current head of the Quirra River is well developed. The Quirra River, in its upstream part, flows at altitudes approximately 200 m higher than the Pardu River. It also shows an oversized and over-flooded valley with respect to the catchment area upstream. This setting indicates that the Pardu River, which previously flowed south along the Quirra River, was captured by the Pelau River. We analyzed long-term landslides with lateral spreading and sackung characteristics, which involve giant carbonate blocks and underlying foliated metamorphites in both valleys. The use of LiDAR, high-resolution uncrewed aerial vehicle digital photogrammetry (UAV-DP), and geological, structural, and geomorphological surveys enabled a depth morphometric analysis and the creation of interpretative 3D models of DGSDs. Space-borne interferometric synthetic aperture radar (InSAR) data using ERS and Sentinel-1 satellites identified downslope movement of up to 20 mm per year in both Pardu Valley flanks. Multi-source and multi-scale data showed that the state of activity of the DGSDs is closely linked to the geomorphological evolution of the catchment areas of the Rio Pardu and Rio Quirra. The intense post-capture erosion acted in the Rio Pardu Valley, giving it morphometric characteristics that were favorable to the current evolution of the DGSDs, while the Rio Quirra Valley presents paleo-DGSDs that have been fossilized by pre-capture terraced alluvial deposits.

In this study, we analyse deep-seated gravitational slope deformations (DSGSDs) in central Sardinia. The area is characterised by plateaus with a prominent limestone scarp overlying metamorphites. A comprehensive mapping of structural, karst, fluvial, and slope morphologies in Pardu and Ulassai valleys is presented herein. The uplift linked to the Plio-Pleistocene tectonic activity leads to high-slope topography, which favours gravitational processes, such as DSGSDs and rock-avalanches. Although DSGSD is a common phenomenon in the relief of the central Mediterranean region, it has never been studied in Sardinia. We describe the kinematic models and geomorphological evolution of DSGSD in Sardinia for the first time. The application of light detection and ranging, high-resolution unmanned aerial vehicle photogrammetry, and geological, structural, and geomorphological surveys enabled a depth morphometric analysis and the development of interpretative three-dimensional models. The geo-structural setting and high relief energy associated with recent upliftment are the major controlling factors of DSGSDs.