Recognition of landslides in lunar impact craters

Abstract

Landslides have been observed on several planets and minor bodies of the solar System, including the Moon. Notwithstanding different types of slope failures have been studied on the Moon, a detailed lunar landslide inventory is still pending. Undoubtedly, such will be in a benefit for future geological and morphological studies, as well in hazard, risk and suscept- ibility assessments. A preliminary survey of lunar landslides in impact craters has been done using visual inspection on images and digital elevation model (DEM) (Brunetti et al. 2015) but this method suffers from subjective interpretation. A new methodology based on polynomial interpolation of crater cross-sections extracted from global lunar DEMs is presented in this paper. Because of their properties, Chebyshev polynomials were already exploited for para- metric classification of different crater morphologies (Mahanti et al., 2014). Here, their use has been extended to the discrimination of slumps in simple impact craters. Two criteria for recognition have provided the best results: one based on fixing an empirical absolute thresholding and a second based on statistical adaptive thresholding. The application of both criteria to a data set made up of 204 lunar craters’ cross-sections has demonstrated that the former criterion provides the best recognition

Geologic Analyses of the Causes of Morphological Variations in Lunar Craters Within the Simple‐to‐Complex Transition

“…Conversely, the absence of a prominent topographic hindrance could lessen the probability of over steepening, thus driving the stabilization of the cavity and resulting in simple craters. These terrain correlations are demonstrated by close‐proximity group D. The geologic settings of simple craters and of 35% of the craters bearing localized slumped material in the highlands appear to be similar, supported by our observations on terrains of close‐proximity groups B, C, J, and K. The morphological differences in similar geologic settings could be the result of multiple causes: relatively older craters undergoing slumping post crater formation from seismic shaking (Brunetti et al, ; Izenberg, ; Kumar et al, ; Scaioni et al, ), abrupt topographic variation obscured by regolith or ejecta blankets of surrounding craters, unrecognized target properties (such as highland material of strength that is low enough to facilitate sliding under gravity), or impactor properties such as impact velocity, impactor size, and density. The similar target geology of craters in Groups B and J suggests the primary involvement of impactor properties that result in the observed morphological differences among craters in each group (see section for discussion on impactor properties).…”

“…However, we could not find any craters with such signatures of localized floor material. It could be possible that the change in wall slope is caused by localized slumping that could occur immediately after transient cavity formation as part of the modification phase of crater formation (Melosh, ; Quaide et al, ; Settle & Head, ), or material could potentially slump off the walls much later, triggered by some process such as seismic shaking from a later impact (Brunetti et al, ; Izenberg, ; Kumar et al, ; Scaioni et al, ). To test whether our database consists of crater structures characteristic of both the processes, we performed crater counting on the ejecta and slumped material of few randomly selected, though similar‐sized craters to compare the relative ages of the unconsolidated floor material with that of the ejecta.…”

“…The low strength of the target material and/or hidden heterogeneities in the basin ejecta may be responsible for the minor localized slumping observed (Aschauer & Kenkmann, 2017). Furthermore, the possibility of slumping from post-crater modification (Kumar et al, 2013;Scaioni et al, 2018) cannot be ruled out.…”

Impacts drive lunar rockfalls over billions of years

“…However, recently acquired, high-resolution imagery has revealed a startling feature on lunar slopes: ubiquitous mass-wasting features. These include granular flows 4,5 , slides, slumps, and creeps 1,6 , as well as rockfalls 1,[7][8][9] , a process where boulders are released or ejected from topographic highs and fall, roll, bounce, and slide to topographic lows. Rockfalls carve tracks into the lunar surface, which provide a record of the dynamic emplacement process.…”

Technical Aspects Related to the Application of SFM Photogrammetry in High Mountain

“…It is worth to mention that also satellite images at medium resolution maybe used for static and dynamic modelling of some phenomena in remote geographic location or before the era of high-resolution imagery. Examples of such applications are extraterrestrial mapping (see, e.g., Scaioni et al, 2018a) or Antarctic research (see Li et al, 2016). Last but not least, microwave remote sensing may provide DEM's covering entire regions or the whole globe, as in the case of SRTM (Bertiér et al, 2006) global model.…”