Deformation of the Gruithuisen region lava tube under compressional stress on the Moon

The lava tube in the Gruithuisen region on the Moon is intriguing because it is characterized by a distinctive chain of collapsed pits and raised features, providing an opportunity to understand the potential morphologic deformation of lunar lava tubes under compressional stress. This study aimed to understand the morphological deformation in the Gruithuisen region's lava tube when subjected to compressional stress. A combination of numerical simulations and morphometric analysis was employed to achieve this objective. The morphometric analysis of different collapsed and raised features associated with a lava tube in the study area revealed eight characteristic morphologies ranging from curvilinear channel-like to elliptical shape. Notably, average normal stress and strain values derived from a wrinkle ridge were found to be similar to 70 MPa and 2 x 10-3, respectively, and wrinkle ridges exhibited a northward orientation. These quantified parameters were utilized as the foundation for initializing threedimensional models. Furthermore, the outcomes of the models closely replicated the deformation in the Gruithuisen region, emphasizing the significant role of compressional stress in the deformation of the lava tube. These models suggest that the observed eight unique features associated with the lava tube arise from disparities in displacement magnitude and direction along three axes (x, y, z). Our research sheds light on the structural transformations of lava tubes when subjected to varying compressional stress and enhances understanding of the ways in which the interplay between compressional tectonic activity and lava tube features has shaped the Moon's surface.